2 This file is part of GNUnet.
3 (C) 2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
23 #include "gnunet_util_lib.h"
25 #include "gnunet_statistics_service.h"
28 #include "mesh_protocol.h"
30 #include "gnunet-service-mesh_channel.h"
31 #include "gnunet-service-mesh_local.h"
32 #include "gnunet-service-mesh_tunnel.h"
33 #include "gnunet-service-mesh_peer.h"
35 #define LOG(level, ...) GNUNET_log_from(level,"mesh-chn",__VA_ARGS__)
37 #define MESH_RETRANSMIT_TIME GNUNET_TIME_UNIT_SECONDS
38 #define MESH_RETRANSMIT_MARGIN 4
42 * All the states a connection can be in.
47 * Uninitialized status, should never appear in operation.
52 * Connection create message sent, waiting for ACK.
57 * Connection confirmed, ready to carry traffic.
64 * Info holder for channel messages in queues.
66 struct MeshChannelQueue
71 struct MeshTunnel3Queue *q;
74 * Message type (DATA/DATA_ACK)
79 * Message copy (for DATAs, to start retransmission timer)
81 struct MeshReliableMessage *copy;
84 * Reliability (for DATA_ACKs, to access rel->ack_q)
86 struct MeshChannelReliability *rel;
91 * Info needed to retry a message in case it gets lost.
93 struct MeshReliableMessage
96 * Double linked list, FIFO style
98 struct MeshReliableMessage *next;
99 struct MeshReliableMessage *prev;
102 * Type of message (payload, channel management).
107 * Tunnel Reliability queue this message is in.
109 struct MeshChannelReliability *rel;
112 * ID of the message (ACK needed to free)
119 struct MeshTunnel3Queue *q;
122 * When was this message issued (to calculate ACK delay)
124 struct GNUNET_TIME_Absolute timestamp;
126 /* struct GNUNET_MESH_Data with payload */
131 * Info about the traffic state for a client in a channel.
133 struct MeshChannelReliability
136 * Channel this is about.
138 struct MeshChannel *ch;
141 * DLL of messages sent and not yet ACK'd.
143 struct MeshReliableMessage *head_sent;
144 struct MeshReliableMessage *tail_sent;
147 * DLL of messages received out of order.
149 struct MeshReliableMessage *head_recv;
150 struct MeshReliableMessage *tail_recv;
158 * Next MID to use for outgoing traffic.
163 * Next MID expected for incoming traffic.
168 * Handle for queued DATA_ACKs.
170 struct MeshChannelQueue *ack_q;
173 * Can we send data to the client?
178 * Can the client send data to us?
183 * Task to resend/poll in case no ACK is received.
185 GNUNET_SCHEDULER_TaskIdentifier retry_task;
188 * Counter for exponential backoff.
190 struct GNUNET_TIME_Relative retry_timer;
193 * How long does it usually take to get an ACK.
195 struct GNUNET_TIME_Relative expected_delay;
200 * Struct containing all information regarding a channel to a remote client.
205 * Tunnel this channel is in.
207 struct MeshTunnel3 *t;
210 * Destination port of the channel.
215 * Global channel number ( < GNUNET_MESH_LOCAL_CHANNEL_ID_CLI)
217 MESH_ChannelNumber gid;
220 * Local tunnel number for root (owner) client.
221 * ( >= GNUNET_MESH_LOCAL_CHANNEL_ID_CLI or 0 )
223 MESH_ChannelNumber lid_root;
226 * Local tunnel number for local destination clients (incoming number)
227 * ( >= GNUNET_MESH_LOCAL_CHANNEL_ID_SERV or 0).
229 MESH_ChannelNumber lid_dest;
234 enum MeshChannelState state;
237 * Is the tunnel bufferless (minimum latency)?
242 * Is the tunnel reliable?
247 * Last time the channel was used
249 struct GNUNET_TIME_Absolute timestamp;
252 * Client owner of the tunnel, if any
254 struct MeshClient *root;
257 * Client destination of the tunnel, if any.
259 struct MeshClient *dest;
262 * Flag to signal the destruction of the channel.
263 * If this is set GNUNET_YES the channel will be destroyed
264 * when the queue is empty.
269 * Total (reliable) messages pending ACK for this channel.
271 unsigned int pending_messages;
275 * Only present (non-NULL) at the owner of a tunnel.
277 struct MeshChannelReliability *root_rel;
281 * Only present (non-NULL) at the destination of a tunnel.
283 struct MeshChannelReliability *dest_rel;
288 /******************************************************************************/
289 /******************************* GLOBALS ***********************************/
290 /******************************************************************************/
293 * Global handle to the statistics service.
295 extern struct GNUNET_STATISTICS_Handle *stats;
298 * Local peer own ID (memory efficient handle).
300 extern GNUNET_PEER_Id myid;
303 /******************************************************************************/
304 /******************************** STATIC ***********************************/
305 /******************************************************************************/
308 * Destroy a reliable message after it has been acknowledged, either by
309 * direct mid ACK or bitfield. Updates the appropriate data structures and
310 * timers and frees all memory.
312 * @param copy Message that is no longer needed: remote peer got it.
313 * @param update_time Is the timing information relevant?
314 * If this message is ACK in a batch the timing information
315 * is skewed by the retransmission, count only for the
316 * retransmitted message.
319 rel_message_free (struct MeshReliableMessage *copy, int update_time);
322 * We have received a message out of order, or the client is not ready.
323 * Buffer it until we receive an ACK from the client or the missing
324 * message from the channel.
326 * @param msg Message to buffer (MUST be of type MESH_DATA).
327 * @param rel Reliability data to the corresponding direction.
330 add_buffered_data (const struct GNUNET_MESH_Data *msg,
331 struct MeshChannelReliability *rel)
333 struct MeshReliableMessage *copy;
334 struct MeshReliableMessage *prev;
338 size = ntohs (msg->header.size);
339 mid = ntohl (msg->mid);
341 LOG (GNUNET_ERROR_TYPE_DEBUG, "add_buffered_data %u\n", mid);
343 copy = GNUNET_malloc (sizeof (*copy) + size);
346 copy->type = GNUNET_MESSAGE_TYPE_MESH_DATA;
347 memcpy (©[1], msg, size);
351 // FIXME do something better than O(n), although n < 64...
352 // FIXME start from the end (most messages are the latest ones)
353 for (prev = rel->head_recv; NULL != prev; prev = prev->next)
355 LOG (GNUNET_ERROR_TYPE_DEBUG, " prev %u\n", prev->mid);
356 if (GM_is_pid_bigger (prev->mid, mid))
358 LOG (GNUNET_ERROR_TYPE_DEBUG, " bingo!\n");
359 GNUNET_CONTAINER_DLL_insert_before (rel->head_recv, rel->tail_recv,
364 LOG (GNUNET_ERROR_TYPE_DEBUG, " insert at tail!\n");
365 GNUNET_CONTAINER_DLL_insert_tail (rel->head_recv, rel->tail_recv, copy);
366 LOG (GNUNET_ERROR_TYPE_DEBUG, "add_buffered_data END\n");
370 * Add a destination client to a channel, initializing all data structures
371 * in the channel and the client.
373 * @param ch Channel to which add the destination.
374 * @param c Client which to add to the channel.
377 add_destination (struct MeshChannel *ch, struct MeshClient *c)
379 if (NULL != ch->dest)
385 /* Assign local id as destination */
386 ch->lid_dest = GML_get_next_chid (c);
388 /* Store in client's hashmap */
389 GML_channel_add (c, ch->lid_dest, ch);
391 GNUNET_break (NULL == ch->dest_rel);
392 ch->dest_rel = GNUNET_new (struct MeshChannelReliability);
393 ch->dest_rel->ch = ch;
394 ch->dest_rel->expected_delay = MESH_RETRANSMIT_TIME;
401 * Send data to a client.
403 * If the client is ready, send directly, otherwise buffer while listening
407 * @param msg Message.
408 * @param fwd Is this a fwd (root->dest) message?
411 send_client_data (struct MeshChannel *ch,
412 const struct GNUNET_MESH_Data *msg,
417 if (ch->dest_rel->client_ready)
418 GML_send_data (ch->dest, msg, ch->lid_dest);
420 add_buffered_data (msg, ch->dest_rel);
424 if (ch->root_rel->client_ready)
425 GML_send_data (ch->root, msg, ch->lid_root);
427 add_buffered_data (msg, ch->root_rel);
433 * Send a buffered message to the client, for in order delivery or
434 * as result of client ACK.
436 * @param ch Channel on which to empty the message buffer.
437 * @param c Client to send to.
438 * @param fwd Is this to send FWD data?.
441 send_client_buffered_data (struct MeshChannel *ch,
442 struct MeshClient *c,
445 struct MeshReliableMessage *copy;
446 struct MeshChannelReliability *rel;
448 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data\n");
449 rel = fwd ? ch->dest_rel : ch->root_rel;
450 if (GNUNET_NO == rel->client_ready)
452 LOG (GNUNET_ERROR_TYPE_DEBUG, "client not ready\n");
456 copy = rel->head_recv;
457 /* We never buffer channel management messages */
460 if (copy->mid == rel->mid_recv || GNUNET_NO == ch->reliable)
462 struct GNUNET_MESH_Data *msg = (struct GNUNET_MESH_Data *) ©[1];
464 LOG (GNUNET_ERROR_TYPE_DEBUG,
465 " have %u! now expecting %u\n",
466 copy->mid, rel->mid_recv + 1);
467 send_client_data (ch, msg, fwd);
470 GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy);
475 LOG (GNUNET_ERROR_TYPE_DEBUG,
476 " reliable && don't have %u, next is %u\n",
482 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data END\n");
487 * Allow a client to send more data.
489 * In case the client was already allowed to send data, do nothing.
492 * @param fwd Is this a FWD ACK? (FWD ACKs are sent to root)
495 send_client_ack (struct MeshChannel *ch, int fwd)
497 struct MeshChannelReliability *rel = fwd ? ch->root_rel : ch->dest_rel;
499 LOG (GNUNET_ERROR_TYPE_DEBUG,
500 " sending %s ack to client on channel %s\n",
501 GM_f2s (fwd), GMCH_2s (ch));
509 if (GNUNET_YES == rel->client_allowed)
511 LOG (GNUNET_ERROR_TYPE_DEBUG, " already allowed\n");
514 rel->client_allowed = GNUNET_YES;
516 GML_send_ack (fwd ? ch->root : ch->dest, fwd ? ch->lid_root : ch->lid_dest);
521 * Notify the root that the destination rejected the channel.
523 * @param ch Rejected channel.
526 send_client_nack (struct MeshChannel *ch)
528 if (NULL == ch->root)
533 GML_send_nack (ch->root, ch->lid_root);
538 * Notify a client that the channel is no longer valid.
540 * @param ch Channel that is destroyed.
541 * @param local_only Should we avoid sending it to other peers?
544 send_destroy (struct MeshChannel *ch, int local_only)
546 struct GNUNET_MESH_ChannelManage msg;
548 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY);
549 msg.header.size = htons (sizeof (msg));
550 msg.chid = htonl (ch->gid);
552 /* If root is not NULL, notify.
553 * If it's NULL, check lid_root. When a local destroy comes in, root
554 * is set to NULL but lid_root is left untouched. In this case, do nothing,
555 * the client is the one who reuqested the channel to be destroyed.
557 if (NULL != ch->root)
558 GML_send_channel_destroy (ch->root, ch->lid_root);
559 else if (0 == ch->lid_root && GNUNET_NO == local_only)
560 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO, NULL);
562 if (NULL != ch->dest)
563 GML_send_channel_destroy (ch->dest, ch->lid_dest);
564 else if (0 == ch->lid_dest && GNUNET_NO == local_only)
565 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_YES, NULL);
570 * Destroy all reliable messages queued for a channel,
571 * during a channel destruction.
572 * Frees the reliability structure itself.
574 * @param rel Reliability data for a channel.
577 channel_rel_free_all (struct MeshChannelReliability *rel)
579 struct MeshReliableMessage *copy;
580 struct MeshReliableMessage *next;
585 for (copy = rel->head_recv; NULL != copy; copy = next)
588 GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy);
591 for (copy = rel->head_sent; NULL != copy; copy = next)
594 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
597 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
598 GNUNET_SCHEDULER_cancel (rel->retry_task);
599 if (NULL != rel->ack_q)
600 GMT_cancel (rel->ack_q->q);
606 * Mark future messages as ACK'd.
608 * @param rel Reliability data.
609 * @param msg DataACK message with a bitfield of future ACK'd messages.
612 channel_rel_free_sent (struct MeshChannelReliability *rel,
613 const struct GNUNET_MESH_DataACK *msg)
615 struct MeshReliableMessage *copy;
616 struct MeshReliableMessage *next;
623 bitfield = msg->futures;
624 mid = ntohl (msg->mid);
625 LOG (GNUNET_ERROR_TYPE_DEBUG,
626 "!!! free_sent_reliable %u %llX\n",
628 LOG (GNUNET_ERROR_TYPE_DEBUG,
629 " rel %p, head %p\n",
630 rel, rel->head_sent);
631 for (i = 0, copy = rel->head_sent;
632 i < 64 && NULL != copy && 0 != bitfield;
635 LOG (GNUNET_ERROR_TYPE_DEBUG,
636 " trying bit %u (mid %u)\n",
639 if (0 == (bitfield & mask))
642 LOG (GNUNET_ERROR_TYPE_DEBUG, " set!\n");
643 /* Bit was set, clear the bit from the bitfield */
646 /* The i-th bit was set. Do we have that copy? */
647 /* Skip copies with mid < target */
648 target = mid + i + 1;
649 LOG (GNUNET_ERROR_TYPE_DEBUG, " target %u\n", target);
650 while (NULL != copy && GM_is_pid_bigger (target, copy->mid))
653 /* Did we run out of copies? (previously freed, it's ok) */
656 LOG (GNUNET_ERROR_TYPE_DEBUG, "run out of copies...\n");
660 /* Did we overshoot the target? (previously freed, it's ok) */
661 if (GM_is_pid_bigger (copy->mid, target))
663 LOG (GNUNET_ERROR_TYPE_DEBUG, " next copy %u\n", copy->mid);
667 /* Now copy->mid == target, free it */
669 rel_message_free (copy, GNUNET_YES);
672 LOG (GNUNET_ERROR_TYPE_DEBUG, "free_sent_reliable END\n");
677 * We haven't received an ACK after a certain time: restransmit the message.
679 * @param cls Closure (MeshReliableMessage with the message to restransmit)
680 * @param tc TaskContext.
683 channel_retransmit_message (void *cls,
684 const struct GNUNET_SCHEDULER_TaskContext *tc)
686 struct MeshChannelReliability *rel = cls;
687 struct MeshReliableMessage *copy;
688 struct MeshChannel *ch;
689 struct GNUNET_MESH_Data *payload;
692 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
693 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
697 copy = rel->head_sent;
704 payload = (struct GNUNET_MESH_Data *) ©[1];
705 fwd = (rel == ch->root_rel);
707 /* Message not found in the queue that we are going to use. */
708 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RETRANSMIT %u\n", copy->mid);
710 GMCH_send_prebuilt_message (&payload->header, ch, fwd, copy);
711 GNUNET_STATISTICS_update (stats, "# data retransmitted", 1, GNUNET_NO);
716 * Destroy a reliable message after it has been acknowledged, either by
717 * direct mid ACK or bitfield. Updates the appropriate data structures and
718 * timers and frees all memory.
720 * @param copy Message that is no longer needed: remote peer got it.
721 * @param update_time Is the timing information relevant?
722 * If this message is ACK in a batch the timing information
723 * is skewed by the retransmission, count only for the
724 * retransmitted message.
727 rel_message_free (struct MeshReliableMessage *copy, int update_time)
729 struct MeshChannelReliability *rel;
730 struct GNUNET_TIME_Relative time;
733 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Freeing %u\n", copy->mid);
736 time = GNUNET_TIME_absolute_get_duration (copy->timestamp);
737 rel->expected_delay.rel_value_us *= 7;
738 rel->expected_delay.rel_value_us += time.rel_value_us;
739 rel->expected_delay.rel_value_us /= 8;
740 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! took %s\n",
741 GNUNET_STRINGS_relative_time_to_string (time, GNUNET_NO));
742 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! new expected delay %s\n",
743 GNUNET_STRINGS_relative_time_to_string (rel->expected_delay,
745 rel->retry_timer = rel->expected_delay;
749 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! batch free, ignoring timing\n");
751 rel->ch->pending_messages--;
752 if (GNUNET_NO != rel->ch->destroy && 0 == rel->ch->pending_messages)
754 struct MeshTunnel3 *t = rel->ch->t;
755 GMCH_destroy (rel->ch);
756 GMT_destroy_if_empty (t);
758 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
764 * Confirm we got a channel create.
766 * @param ch The channel to confirm.
767 * @param fwd Should we send a FWD ACK? (going dest->root)
770 channel_send_ack (struct MeshChannel *ch, int fwd)
772 struct GNUNET_MESH_ChannelManage msg;
774 msg.header.size = htons (sizeof (msg));
775 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK);
776 LOG (GNUNET_ERROR_TYPE_DEBUG,
777 " sending channel %s ack for channel %s\n",
778 GM_f2s (fwd), GMCH_2s (ch));
780 msg.chid = htonl (ch->gid);
781 GMCH_send_prebuilt_message (&msg.header, ch, !fwd, NULL);
786 * Notify that a channel create didn't succeed.
788 * @param ch The channel to reject.
791 channel_send_nack (struct MeshChannel *ch)
793 struct GNUNET_MESH_ChannelManage msg;
795 msg.header.size = htons (sizeof (msg));
796 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK);
797 LOG (GNUNET_ERROR_TYPE_DEBUG,
798 " sending channel NACK for channel %s\n",
801 msg.chid = htonl (ch->gid);
802 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO, NULL);
807 * Channel was ACK'd by remote peer, mark as ready and cancel retransmission.
809 * @param ch Channel to mark as ready.
810 * @param fwd Was the ACK message a FWD ACK? (dest->root, SYNACK)
813 channel_confirm (struct MeshChannel *ch, int fwd)
815 struct MeshChannelReliability *rel;
816 struct MeshReliableMessage *copy;
817 struct MeshReliableMessage *next;
819 LOG (GNUNET_ERROR_TYPE_DEBUG,
820 " channel confirm %s %s:%X\n",
821 GM_f2s (fwd), GMT_2s (ch->t), ch->gid);
822 ch->state = MESH_CHANNEL_READY;
824 rel = fwd ? ch->root_rel : ch->dest_rel;
825 rel->client_ready = GNUNET_YES;
826 for (copy = rel->head_sent; NULL != copy; copy = next)
828 struct GNUNET_MessageHeader *msg;
831 msg = (struct GNUNET_MessageHeader *) ©[1];
832 if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE)
834 rel_message_free (copy, GNUNET_YES);
838 send_client_ack (ch, fwd);
840 /* In case of a FWD ACK (SYNACK) send a BCK ACK (ACK). */
842 channel_send_ack (ch, !fwd);
847 * Message has been sent: start retransmission timer.
849 * @param cls Closure (queue structure).
851 * @param q Queue handler (no longer valid).
852 * @param type Type of message.
853 * @param size Size of the message.
856 ch_message_sent (void *cls,
857 struct MeshTunnel3 *t,
858 struct MeshTunnel3Queue *q,
859 uint16_t type, size_t size)
861 struct MeshChannelQueue *ch_q = cls;
862 struct MeshReliableMessage *copy = ch_q->copy;
863 struct MeshChannelReliability *rel;
867 case GNUNET_MESSAGE_TYPE_MESH_DATA:
868 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SENT %u %s\n",
869 NULL != copy ? copy->mid : 0, GM_m2s (type));
870 copy->timestamp = GNUNET_TIME_absolute_get ();
872 if (GNUNET_SCHEDULER_NO_TASK == rel->retry_task)
875 GNUNET_TIME_relative_multiply (rel->expected_delay,
876 MESH_RETRANSMIT_MARGIN);
878 GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
879 &channel_retransmit_message,
885 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
887 GNUNET_assert (rel->ack_q == ch_q);
903 * Save a copy to retransmit in case it gets lost.
905 * Initializes all needed callbacks and timers.
907 * @param ch Channel this message goes on.
908 * @param msg Message to copy.
909 * @param fwd Is this fwd traffic?
911 static struct MeshReliableMessage *
912 channel_save_copy (struct MeshChannel *ch,
913 const struct GNUNET_MessageHeader *msg,
916 struct MeshChannelReliability *rel;
917 struct MeshReliableMessage *copy;
922 rel = fwd ? ch->root_rel : ch->dest_rel;
923 mid = rel->mid_send - 1;
924 type = ntohs (msg->type);
925 size = ntohs (msg->size);
927 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SAVE %u %s\n", mid, GM_m2s (type));
928 copy = GNUNET_malloc (sizeof (struct MeshReliableMessage) + size);
932 memcpy (©[1], msg, size);
933 GNUNET_CONTAINER_DLL_insert_tail (rel->head_sent, rel->tail_sent, copy);
934 ch->pending_messages++;
941 * Create a new channel.
943 * @param t Tunnel this channel is in.
944 * @param owner Client that owns the channel, NULL for foreign channels.
945 * @param lid_root Local ID for root client.
947 * @return A new initialized channel. NULL on error.
949 static struct MeshChannel *
950 channel_new (struct MeshTunnel3 *t,
951 struct MeshClient *owner,
952 MESH_ChannelNumber lid_root)
954 struct MeshChannel *ch;
956 ch = GNUNET_new (struct MeshChannel);
958 ch->lid_root = lid_root;
961 GNUNET_STATISTICS_update (stats, "# channels", 1, GNUNET_NO);
965 ch->gid = GMT_get_next_chid (t);
966 GML_channel_add (owner, lid_root, ch);
968 GMT_add_channel (t, ch);
975 * Set options in a channel, extracted from a bit flag field
977 * @param ch Channel to set options to.
978 * @param options Bit array in host byte order.
981 channel_set_options (struct MeshChannel *ch, uint32_t options)
983 ch->nobuffer = (options & GNUNET_MESH_OPTION_NOBUFFER) != 0 ?
984 GNUNET_YES : GNUNET_NO;
985 ch->reliable = (options & GNUNET_MESH_OPTION_RELIABLE) != 0 ?
986 GNUNET_YES : GNUNET_NO;
990 is_loopback (const struct MeshChannel *ch)
993 return GMT_is_loopback (ch->t);
995 return (NULL != ch->root && NULL != ch->dest);
1000 * Handle a loopback message: call the appropriate handler for the message type.
1002 * @param ch Channel this message is on.
1003 * @param msgh Message header.
1004 * @param fwd Is this FWD traffic?
1007 handle_loopback (struct MeshChannel *ch,
1008 const struct GNUNET_MessageHeader *msgh,
1013 type = ntohs (msgh->type);
1014 LOG (GNUNET_ERROR_TYPE_DEBUG,
1015 "Loopback %s %s message!\n",
1016 GM_f2s (fwd), GM_m2s (type));
1020 case GNUNET_MESSAGE_TYPE_MESH_DATA:
1021 /* Don't send hop ACK, wait for client to ACK */
1022 GMCH_handle_data (ch, (struct GNUNET_MESH_Data *) msgh, fwd);
1025 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
1026 GMCH_handle_data_ack (ch, (struct GNUNET_MESH_DataACK *) msgh, fwd);
1029 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
1030 GMCH_handle_create (ch->t,
1031 (struct GNUNET_MESH_ChannelCreate *) msgh);
1034 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
1035 GMCH_handle_ack (ch,
1036 (struct GNUNET_MESH_ChannelManage *) msgh,
1040 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK:
1041 GMCH_handle_nack (ch);
1044 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
1045 GMCH_handle_destroy (ch,
1046 (struct GNUNET_MESH_ChannelManage *) msgh,
1051 GNUNET_break_op (0);
1052 LOG (GNUNET_ERROR_TYPE_DEBUG,
1053 "end-to-end message not known (%u)\n",
1054 ntohs (msgh->type));
1060 /******************************************************************************/
1061 /******************************** API ***********************************/
1062 /******************************************************************************/
1065 * Destroy a channel and free all resources.
1067 * @param ch Channel to destroy.
1070 GMCH_destroy (struct MeshChannel *ch)
1072 struct MeshClient *c;
1077 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying channel %s:%u\n",
1078 GMT_2s (ch->t), ch->gid);
1084 GML_channel_remove (c, ch->lid_root, ch);
1090 GML_channel_remove (c, ch->lid_dest, ch);
1093 channel_rel_free_all (ch->root_rel);
1094 channel_rel_free_all (ch->dest_rel);
1096 GMT_remove_channel (ch->t, ch);
1097 GNUNET_STATISTICS_update (stats, "# channels", -1, GNUNET_NO);
1106 * @param ch Channel.
1111 GMCH_get_id (const struct MeshChannel *ch)
1118 * Get the channel tunnel.
1120 * @param ch Channel to get the tunnel from.
1122 * @return tunnel of the channel.
1124 struct MeshTunnel3 *
1125 GMCH_get_tunnel (const struct MeshChannel *ch)
1132 * Get free buffer space towards the client on a specific channel.
1134 * @param ch Channel.
1135 * @param fwd Is query about FWD traffic?
1137 * @return Free buffer space [0 - 64]
1140 GMCH_get_buffer (struct MeshChannel *ch, int fwd)
1142 struct MeshChannelReliability *rel;
1144 rel = fwd ? ch->dest_rel : ch->root_rel;
1146 /* If rel is NULL it means that the end is not yet created,
1147 * most probably is a loopback channel at the point of sending
1148 * the ChannelCreate to itself.
1153 return (64 - rel->n_recv);
1158 * Get flow control status of end point: is client allow to send?
1160 * @param ch Channel.
1161 * @param fwd Is query about FWD traffic? (Request root status).
1163 * @return #GNUNET_YES if client is allowed to send us data.
1166 GMCH_get_allowed (struct MeshChannel *ch, int fwd)
1168 struct MeshChannelReliability *rel;
1170 rel = fwd ? ch->root_rel : ch->dest_rel;
1174 /* Probably shutting down: root/dest NULL'ed to mark disconnection */
1175 GNUNET_break (GNUNET_NO != ch->destroy);
1179 return rel->client_allowed;
1184 * Is the root client for this channel on this peer?
1186 * @param ch Channel.
1187 * @param fwd Is this for fwd traffic?
1189 * @return #GNUNET_YES in case it is.
1192 GMCH_is_origin (struct MeshChannel *ch, int fwd)
1194 struct MeshClient *c;
1196 c = fwd ? ch->root : ch->dest;
1202 * Is the destination client for this channel on this peer?
1204 * @param ch Channel.
1205 * @param fwd Is this for fwd traffic?
1207 * @return #GNUNET_YES in case it is.
1210 GMCH_is_terminal (struct MeshChannel *ch, int fwd)
1212 struct MeshClient *c;
1214 c = fwd ? ch->dest : ch->root;
1220 * Notify the destination client that a new incoming channel was created.
1222 * @param ch Channel that was created.
1225 GMCH_send_create (struct MeshChannel *ch)
1229 if (NULL == ch->dest)
1233 opt |= GNUNET_YES == ch->reliable ? GNUNET_MESH_OPTION_RELIABLE : 0;
1234 opt |= GNUNET_YES == ch->nobuffer ? GNUNET_MESH_OPTION_NOBUFFER : 0;
1235 GML_send_channel_create (ch->dest, ch->lid_dest, ch->port, opt,
1236 GMT_get_destination (ch->t));
1242 * Send an end-to-end ACK message for the most recent in-sequence payload.
1244 * If channel is not reliable, do nothing.
1246 * @param ch Channel this is about.
1247 * @param fwd Is for FWD traffic? (ACK dest->owner)
1250 GMCH_send_data_ack (struct MeshChannel *ch, int fwd)
1252 struct GNUNET_MESH_DataACK msg;
1253 struct MeshChannelReliability *rel;
1254 struct MeshReliableMessage *copy;
1259 if (GNUNET_NO == ch->reliable)
1263 rel = fwd ? ch->dest_rel : ch->root_rel;
1264 ack = rel->mid_recv - 1;
1265 LOG (GNUNET_ERROR_TYPE_DEBUG,
1266 " !! Send DATA_ACK for %u\n",
1269 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_DATA_ACK);
1270 msg.header.size = htons (sizeof (msg));
1271 msg.chid = htonl (ch->gid);
1273 for (copy = rel->head_recv; NULL != copy; copy = copy->next)
1275 if (copy->type != GNUNET_MESSAGE_TYPE_MESH_DATA)
1277 LOG (GNUNET_ERROR_TYPE_DEBUG,
1278 "!! Type %s, expected DATA\n",
1279 GM_m2s (copy->type));
1282 if (copy->mid == ack + 1)
1287 delta = copy->mid - (ack + 1);
1290 mask = 0x1LL << delta;
1291 msg.futures |= mask;
1292 LOG (GNUNET_ERROR_TYPE_DEBUG,
1293 " !! setting bit for %u (delta %u) (%llX) -> %llX\n",
1294 copy->mid, delta, mask, msg.futures);
1296 msg.mid = htonl (ack);
1297 LOG (GNUNET_ERROR_TYPE_DEBUG,
1298 "!!! ACK for %u, futures %llX\n",
1301 GMCH_send_prebuilt_message (&msg.header, ch, !fwd, NULL);
1302 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_data_ack END\n");
1307 * Allow a client to send us more data, in case it was choked.
1309 * @param ch Channel.
1310 * @param fwd Is this about FWD traffic? (Root client).
1313 GMCH_allow_client (struct MeshChannel *ch, int fwd)
1315 struct MeshChannelReliability *rel;
1316 unsigned int buffer;
1318 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH allow\n");
1320 if (MESH_CHANNEL_READY != ch->state)
1322 LOG (GNUNET_ERROR_TYPE_DEBUG, " channel not ready yet!\n");
1326 if (GNUNET_YES == ch->reliable)
1328 rel = fwd ? ch->root_rel : ch->dest_rel;
1331 GNUNET_break (GNUNET_NO != ch->destroy);
1334 if (NULL != rel->head_sent && 64 <= rel->mid_send - rel->head_sent->mid)
1336 LOG (GNUNET_ERROR_TYPE_DEBUG, " too big MID gap! Wait for ACK.\n");
1341 if (is_loopback (ch))
1342 buffer = GMCH_get_buffer (ch, fwd);
1344 buffer = GMT_get_connections_buffer (ch->t);
1348 LOG (GNUNET_ERROR_TYPE_DEBUG, " no buffer space.\n");
1352 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space %u, allowing\n", buffer);
1353 send_client_ack (ch, fwd);
1360 * @param ch Channel.
1363 GMCH_debug (struct MeshChannel *ch)
1367 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CHANNEL ***\n");
1370 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %s:%X (%p)\n",
1371 GMT_2s (ch->t), ch->gid, ch);
1372 LOG (GNUNET_ERROR_TYPE_DEBUG, " root %p/%p\n",
1373 ch->root, ch->root_rel);
1374 if (NULL != ch->root)
1376 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->root));
1377 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1378 ch->root_rel->client_ready ? "YES" : "NO");
1379 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_root);
1381 LOG (GNUNET_ERROR_TYPE_DEBUG, " dest %p/%p\n",
1382 ch->dest, ch->dest_rel);
1383 if (NULL != ch->dest)
1385 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->dest));
1386 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1387 ch->dest_rel->client_ready ? "YES" : "NO");
1388 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_dest);
1394 * Handle an ACK given by a client.
1396 * Mark client as ready and send him any buffered data we could have for him.
1398 * @param ch Channel.
1399 * @param fwd Is this a "FWD ACK"? (FWD ACKs are sent by dest and go BCK)
1402 GMCH_handle_local_ack (struct MeshChannel *ch, int fwd)
1404 struct MeshChannelReliability *rel;
1405 struct MeshClient *c;
1407 rel = fwd ? ch->dest_rel : ch->root_rel;
1408 c = fwd ? ch->dest : ch->root;
1410 rel->client_ready = GNUNET_YES;
1411 send_client_buffered_data (ch, c, fwd);
1412 if (is_loopback (ch))
1414 unsigned int buffer;
1416 buffer = GMCH_get_buffer (ch, fwd);
1418 GMCH_allow_client (ch, fwd);
1422 GMT_send_connection_acks (ch->t);
1427 * Handle data given by a client.
1429 * Check whether the client is allowed to send in this tunnel, save if channel
1430 * is reliable and send an ACK to the client if there is still buffer space
1433 * @param ch Channel.
1434 * @param c Client which sent the data.
1435 * @param message Message.
1436 * @param fwd Is this a FWD data?
1438 * @return GNUNET_OK if everything goes well, GNUNET_SYSERR in case of en error.
1441 GMCH_handle_local_data (struct MeshChannel *ch,
1442 struct MeshClient *c,
1443 struct GNUNET_MessageHeader *message,
1446 struct MeshChannelReliability *rel;
1447 struct GNUNET_MESH_Data *payload;
1448 size_t size = ntohs (message->size);
1449 uint16_t p2p_size = sizeof(struct GNUNET_MESH_Data) + size;
1450 unsigned char cbuf[p2p_size];
1452 /* Is the client in the channel? */
1459 GNUNET_break_op (0);
1460 return GNUNET_SYSERR;
1463 rel = fwd ? ch->root_rel : ch->dest_rel;
1465 if (GNUNET_NO == rel->client_allowed)
1467 GNUNET_break_op (0);
1468 return GNUNET_SYSERR;
1471 rel->client_allowed = GNUNET_NO;
1473 /* Ok, everything is correct, send the message. */
1474 payload = (struct GNUNET_MESH_Data *) cbuf;
1475 payload->mid = htonl (rel->mid_send);
1477 memcpy (&payload[1], message, size);
1478 payload->header.size = htons (p2p_size);
1479 payload->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_DATA);
1480 payload->chid = htonl (ch->gid);
1481 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channel...\n");
1482 GMCH_send_prebuilt_message (&payload->header, ch, fwd, NULL);
1484 if (is_loopback (ch))
1486 if (GMCH_get_buffer (ch, fwd) > 0)
1487 send_client_ack (ch, fwd);
1492 if (GMT_get_connections_buffer (ch->t) > 0)
1494 send_client_ack (ch, fwd);
1502 * Handle a channel destroy requested by a client.
1504 * Destroy the channel and the tunnel in case this was the last channel.
1506 * @param ch Channel.
1507 * @param c Client that requested the destruction (to avoid notifying him).
1508 * @param is_root Is the request coming from root?
1511 GMCH_handle_local_destroy (struct MeshChannel *ch,
1512 struct MeshClient *c,
1515 struct MeshTunnel3 *t;
1517 ch->destroy = GNUNET_YES;
1518 /* Cleanup after the tunnel */
1519 if (GNUNET_NO == is_root && c == ch->dest)
1521 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is destination.\n", GML_2s (c));
1522 GML_client_delete_channel (c, ch, ch->lid_dest);
1525 if (GNUNET_YES == is_root && c == ch->root)
1527 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is owner.\n", GML_2s (c));
1528 GML_client_delete_channel (c, ch, ch->lid_root);
1533 send_destroy (ch, GNUNET_NO);
1534 if (0 == ch->pending_messages)
1537 GMT_destroy_if_empty (t);
1543 * Handle a channel create requested by a client.
1545 * Create the channel and the tunnel in case this was the first0 channel.
1547 * @param c Client that requested the creation (will be the root).
1548 * @param msg Create Channel message.
1550 * @return GNUNET_OK if everything went fine, GNUNET_SYSERR otherwise.
1553 GMCH_handle_local_create (struct MeshClient *c,
1554 struct GNUNET_MESH_ChannelMessage *msg)
1556 struct MeshChannel *ch;
1557 struct MeshTunnel3 *t;
1558 struct MeshPeer *peer;
1559 MESH_ChannelNumber chid;
1561 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s:%u\n",
1562 GNUNET_i2s (&msg->peer), ntohl (msg->port));
1563 chid = ntohl (msg->channel_id);
1565 /* Sanity check for duplicate channel IDs */
1566 if (NULL != GML_channel_get (c, chid))
1569 return GNUNET_SYSERR;
1572 peer = GMP_get (&msg->peer);
1573 GMP_add_tunnel (peer);
1574 t = GMP_get_tunnel (peer);
1576 if (GMP_get_short_id (peer) == myid)
1578 GMT_change_cstate (t, MESH_TUNNEL3_READY);
1585 /* Create channel */
1586 ch = channel_new (t, c, chid);
1590 return GNUNET_SYSERR;
1592 ch->port = ntohl (msg->port);
1593 channel_set_options (ch, ntohl (msg->opt));
1595 /* In unreliable channels, we'll use the DLL to buffer BCK data */
1596 ch->root_rel = GNUNET_new (struct MeshChannelReliability);
1597 ch->root_rel->ch = ch;
1598 ch->root_rel->expected_delay = MESH_RETRANSMIT_TIME;
1600 LOG (GNUNET_ERROR_TYPE_DEBUG, "CREATED CHANNEL %s\n", GMCH_2s (ch));
1602 /* Send create channel */
1604 struct GNUNET_MESH_ChannelCreate msgcc;
1606 msgcc.header.size = htons (sizeof (msgcc));
1607 msgcc.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE);
1608 msgcc.chid = htonl (ch->gid);
1609 msgcc.port = msg->port;
1610 msgcc.opt = msg->opt;
1612 /* FIXME retransmit if lost */
1613 GMT_send_prebuilt_message (&msgcc.header, t, ch,
1614 GNUNET_YES, GNUNET_YES, NULL, NULL);
1621 * Handler for mesh network payload traffic.
1623 * @param ch Channel for the message.
1624 * @param msg Unencryted data message.
1625 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1626 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1627 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1628 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1631 GMCH_handle_data (struct MeshChannel *ch,
1632 const struct GNUNET_MESH_Data *msg,
1635 struct MeshChannelReliability *rel;
1636 struct MeshClient *c;
1639 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1640 if (GNUNET_SYSERR == fwd)
1642 if (is_loopback (ch))
1644 /* It is a loopback channel after all... */
1648 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1651 /* Initialize FWD/BCK data */
1652 c = fwd ? ch->dest : ch->root;
1653 rel = fwd ? ch->dest_rel : ch->root_rel;
1661 GNUNET_STATISTICS_update (stats, "# data received", 1, GNUNET_NO);
1663 mid = ntohl (msg->mid);
1664 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! got mid %u\n", mid);
1666 if (GNUNET_NO == ch->reliable ||
1667 ( !GM_is_pid_bigger (rel->mid_recv, mid) &&
1668 GM_is_pid_bigger (rel->mid_recv + 64, mid) ) )
1670 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RECV %u\n", mid);
1671 if (GNUNET_YES == ch->reliable)
1673 /* Is this the exact next expected messasge? */
1674 if (mid == rel->mid_recv)
1676 LOG (GNUNET_ERROR_TYPE_DEBUG, "as expected\n");
1678 send_client_data (ch, msg, fwd);
1682 LOG (GNUNET_ERROR_TYPE_DEBUG, "save for later\n");
1683 add_buffered_data (msg, rel);
1688 /* Tunnel is unreliable: send to clients directly */
1689 /* FIXME: accept Out Of Order traffic */
1690 rel->mid_recv = mid + 1;
1691 send_client_data (ch, msg, fwd);
1696 GNUNET_break_op (0);
1697 LOG (GNUNET_ERROR_TYPE_DEBUG,
1698 " MID %u not expected (%u - %u), dropping!\n",
1699 mid, rel->mid_recv, rel->mid_recv + 63);
1702 GMCH_send_data_ack (ch, fwd);
1707 * Handler for mesh network traffic end-to-end ACKs.
1709 * @param ch Channel on which we got this message.
1710 * @param msg Data message.
1711 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1712 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1713 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1714 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1717 GMCH_handle_data_ack (struct MeshChannel *ch,
1718 const struct GNUNET_MESH_DataACK *msg,
1721 struct MeshChannelReliability *rel;
1722 struct MeshReliableMessage *copy;
1723 struct MeshReliableMessage *next;
1727 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1728 if (GNUNET_SYSERR == fwd)
1730 if (is_loopback (ch))
1732 /* It is a loopback channel after all... */
1736 /* Inverted: if message came 'FWD' is a 'BCK ACK'. */
1737 fwd = (NULL != ch->dest) ? GNUNET_NO : GNUNET_YES;
1740 ack = ntohl (msg->mid);
1741 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! %s ACK %u\n",
1742 (GNUNET_YES == fwd) ? "FWD" : "BCK", ack);
1744 if (GNUNET_YES == fwd)
1754 GNUNET_break_op (0);
1758 /* Free ACK'd copies: no need to retransmit those anymore */
1759 for (work = GNUNET_NO, copy = rel->head_sent; copy != NULL; copy = next)
1761 if (GM_is_pid_bigger (copy->mid, ack))
1763 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! head %u, out!\n", copy->mid);
1764 channel_rel_free_sent (rel, msg);
1768 LOG (GNUNET_ERROR_TYPE_DEBUG, " !! id %u\n", copy->mid);
1770 rel_message_free (copy, GNUNET_YES);
1773 /* ACK client if needed */
1774 GMCH_allow_client (ch, fwd);
1776 /* If some message was free'd, update the retransmission delay */
1777 if (GNUNET_YES == work)
1779 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
1781 GNUNET_SCHEDULER_cancel (rel->retry_task);
1782 if (NULL == rel->head_sent)
1784 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
1788 struct GNUNET_TIME_Absolute new_target;
1789 struct GNUNET_TIME_Relative delay;
1791 delay = GNUNET_TIME_relative_multiply (rel->retry_timer,
1792 MESH_RETRANSMIT_MARGIN);
1793 new_target = GNUNET_TIME_absolute_add (rel->head_sent->timestamp,
1795 delay = GNUNET_TIME_absolute_get_remaining (new_target);
1797 GNUNET_SCHEDULER_add_delayed (delay,
1798 &channel_retransmit_message,
1809 * Handler for channel create messages.
1811 * Does not have fwd parameter because it's always 'FWD': channel is incoming.
1813 * @param t Tunnel this channel will be in.
1814 * @param msg Channel crate message.
1816 struct MeshChannel *
1817 GMCH_handle_create (struct MeshTunnel3 *t,
1818 const struct GNUNET_MESH_ChannelCreate *msg)
1820 MESH_ChannelNumber chid;
1821 struct MeshChannel *ch;
1822 struct MeshClient *c;
1824 chid = ntohl (msg->chid);
1826 ch = GMT_get_channel (t, chid);
1829 /* Create channel */
1830 ch = channel_new (t, NULL, 0);
1833 channel_set_options (ch, ntohl (msg->opt));
1835 /* Find a destination client */
1836 ch->port = ntohl (msg->port);
1837 LOG (GNUNET_ERROR_TYPE_DEBUG, " port %u\n", ch->port);
1838 c = GML_client_get_by_port (ch->port);
1841 /* TODO send reject */
1842 LOG (GNUNET_ERROR_TYPE_DEBUG, " no client has port registered\n");
1843 if (is_loopback (ch))
1845 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback: destroy on handler\n");
1846 channel_send_nack (ch);
1850 LOG (GNUNET_ERROR_TYPE_DEBUG, " not loopback: destroy now\n");
1851 channel_send_nack (ch);
1858 LOG (GNUNET_ERROR_TYPE_DEBUG, " client %p has port registered\n", c);
1861 add_destination (ch, c);
1862 if (GNUNET_YES == ch->reliable)
1863 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Reliable\n");
1865 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Not Reliable\n");
1867 GMCH_send_create (ch);
1868 channel_send_ack (ch, GNUNET_YES);
1875 * Handler for channel NACK messages.
1877 * NACK messages always go dest -> root, no need for 'fwd' or 'msg' parameter.
1879 * @param ch Channel.
1882 GMCH_handle_nack (struct MeshChannel *ch)
1884 send_client_nack (ch);
1890 * Handler for channel ack messages.
1892 * @param ch Channel.
1893 * @param msg Message.
1894 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1895 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1896 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1897 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1900 GMCH_handle_ack (struct MeshChannel *ch,
1901 const struct GNUNET_MESH_ChannelManage *msg,
1904 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1905 if (GNUNET_SYSERR == fwd)
1907 if (is_loopback (ch))
1909 /* It is a loopback channel after all... */
1913 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1916 channel_confirm (ch, !fwd);
1921 * Handler for channel destroy messages.
1923 * @param ch Channel to be destroyed of.
1924 * @param msg Message.
1925 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1926 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1927 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1928 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1931 GMCH_handle_destroy (struct MeshChannel *ch,
1932 const struct GNUNET_MESH_ChannelManage *msg,
1935 struct MeshTunnel3 *t;
1937 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1938 if (GNUNET_SYSERR == fwd)
1940 if (is_loopback (ch))
1942 /* It is a loopback channel after all... */
1946 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1950 if ( (fwd && NULL == ch->dest) || (!fwd && NULL == ch->root) )
1952 /* Not for us (don't destroy twice a half-open loopback channel) */
1957 send_destroy (ch, GNUNET_YES);
1959 GMT_destroy_if_empty (t);
1964 * Sends an already built message on a channel.
1966 * If the channel is on a loopback tunnel, notifies the appropriate destination
1969 * On a normal channel passes the message to the tunnel for encryption and
1970 * sending on a connection.
1972 * This function DOES NOT save the message for retransmission.
1974 * @param message Message to send. Function makes a copy of it.
1975 * @param ch Channel on which this message is transmitted.
1976 * @param fwd Is this a fwd message?
1977 * @param existing_copy This is a retransmission, don't save a copy.
1980 GMCH_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1981 struct MeshChannel *ch, int fwd,
1982 void *existing_copy)
1986 type = ntohs (message->type);
1987 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH Send %s %s on channel %s\n",
1988 GM_f2s (fwd), GM_m2s (type),
1991 if (GMT_is_loopback (ch->t))
1993 handle_loopback (ch, message, fwd);
1999 case GNUNET_MESSAGE_TYPE_MESH_DATA:
2001 if (GNUNET_YES == ch->reliable)
2003 struct MeshChannelQueue *q;
2005 q = GNUNET_new (struct MeshChannelQueue);
2007 if (NULL == existing_copy)
2008 q->copy = channel_save_copy (ch, message, fwd);
2010 q->copy = (struct MeshReliableMessage *) existing_copy;
2011 q->q = GMT_send_prebuilt_message (message, ch->t, ch,
2012 fwd, NULL != existing_copy,
2013 &ch_message_sent, q);
2014 /* Don't store q itself: we never need to cancel messages */
2018 GNUNET_break (NULL == GMT_send_prebuilt_message (message, ch->t, ch,
2024 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
2026 struct MeshChannelReliability *rel;
2028 rel = fwd ? ch->root_rel : ch->dest_rel;
2029 if (NULL != rel->ack_q)
2031 GMT_cancel (rel->ack_q->q);
2032 /* ch_message_sent is called, freeing ack_q */
2034 rel->ack_q = GNUNET_new (struct MeshChannelQueue);
2035 rel->ack_q->type = type;
2036 rel->ack_q->rel = rel;
2037 rel->ack_q->q = GMT_send_prebuilt_message (message, ch->t, ch,
2039 &ch_message_sent, rel->ack_q);
2043 GNUNET_break (NULL == GMT_send_prebuilt_message (message, ch->t, ch,
2051 * Get the static string for identification of the channel.
2053 * @param ch Channel.
2055 * @return Static string with the channel IDs.
2058 GMCH_2s (const struct MeshChannel *ch)
2060 static char buf[64];
2063 return "(NULL Channel)";
2065 sprintf (buf, "%s:%u gid:%X (%X / %X)",
2066 GMT_2s (ch->t), ch->port, ch->gid, ch->lid_root, ch->lid_dest);