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3 Copyright (C) 2001-2017 GNUnet e.V.
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
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18 SPDX-License-Identifier: AGPL3.0-or-later
21 * @file cadet/gnunet-service-cadet_channel.c
22 * @brief logical links between CADET clients
23 * @author Bartlomiej Polot
24 * @author Christian Grothoff
27 * - Congestion/flow control:
28 * + estimate max bandwidth using bursts and use to for CONGESTION CONTROL!
29 * (and figure out how/where to use this!)
30 * + figure out flow control without ACKs (unreliable traffic!)
31 * - revisit handling of 'unbuffered' traffic!
32 * (need to push down through tunnel into connection selection)
33 * - revisit handling of 'buffered' traffic: 4 is a rather small buffer; maybe
34 * reserve more bits in 'options' to allow for buffer size control?
38 #include "gnunet_statistics_service.h"
39 #include "gnunet-service-cadet_channel.h"
40 #include "gnunet-service-cadet_connection.h"
41 #include "gnunet-service-cadet_tunnels.h"
42 #include "gnunet-service-cadet_paths.h"
44 #define LOG(level,...) GNUNET_log_from (level,"cadet-chn",__VA_ARGS__)
47 * How long do we initially wait before retransmitting?
49 #define CADET_INITIAL_RETRANSMIT_TIME GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 250)
52 * How long do we wait before dropping state about incoming
53 * connection to closed port?
55 #define TIMEOUT_CLOSED_PORT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 30)
58 * How long do we wait at least before retransmitting ever?
60 #define MIN_RTT_DELAY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 75)
63 * Maximum message ID into the future we accept for out-of-order messages.
64 * If the message is more than this into the future, we drop it. This is
65 * important both to detect values that are actually in the past, as well
66 * as to limit adversarially triggerable memory consumption.
68 * Note that right now we have "max_pending_messages = 4" hard-coded in
69 * the logic below, so a value of 4 would suffice here. But we plan to
70 * allow larger windows in the future...
72 #define MAX_OUT_OF_ORDER_DISTANCE 1024
76 * All the states a channel can be in.
78 enum CadetChannelState
81 * Uninitialized status, should never appear in operation.
86 * Channel is to a port that is not open, we're waiting for the
92 * CHANNEL_OPEN message sent, waiting for CHANNEL_OPEN_ACK.
94 CADET_CHANNEL_OPEN_SENT,
97 * Connection confirmed, ready to carry traffic.
104 * Info needed to retry a message in case it gets lost.
105 * Note that we DO use this structure also for unreliable
108 struct CadetReliableMessage
111 * Double linked list, FIFO style
113 struct CadetReliableMessage *next;
116 * Double linked list, FIFO style
118 struct CadetReliableMessage *prev;
121 * Which channel is this message in?
123 struct CadetChannel *ch;
126 * Entry in the tunnels queue for this message, NULL if it has left
127 * the tunnel. Used to cancel transmission in case we receive an
130 struct CadetTunnelQueueEntry *qe;
133 * Data message we are trying to send.
135 struct GNUNET_CADET_ChannelAppDataMessage *data_message;
138 * How soon should we retry if we fail to get an ACK?
139 * Messages in the queue are sorted by this value.
141 struct GNUNET_TIME_Absolute next_retry;
144 * How long do we wait for an ACK after transmission?
145 * Use for the back-off calculation.
147 struct GNUNET_TIME_Relative retry_delay;
150 * Time when we first successfully transmitted the message
151 * (that is, set @e num_transmissions to 1).
153 struct GNUNET_TIME_Absolute first_transmission_time;
156 * Identifier of the connection that this message took when it
157 * was first transmitted. Only useful if @e num_transmissions is 1.
159 struct GNUNET_CADET_ConnectionTunnelIdentifier connection_taken;
162 * How often was this message transmitted? #GNUNET_SYSERR if there
163 * was an error transmitting the message, #GNUNET_NO if it was not
164 * yet transmitted ever, otherwise the number of (re) transmissions.
166 int num_transmissions;
172 * List of received out-of-order data messages.
174 struct CadetOutOfOrderMessage
177 * Double linked list, FIFO style
179 struct CadetOutOfOrderMessage *next;
182 * Double linked list, FIFO style
184 struct CadetOutOfOrderMessage *prev;
187 * ID of the message (messages up to this point needed
188 * before we give this one to the client).
190 struct ChannelMessageIdentifier mid;
193 * The envelope with the payload of the out-of-order message
195 struct GNUNET_MQ_Envelope *env;
201 * Client endpoint of a `struct CadetChannel`. A channel may be a
202 * loopback channel, in which case it has two of these endpoints.
203 * Note that flow control also is required in both directions.
205 struct CadetChannelClient
208 * Client handle. Not by itself sufficient to designate
209 * the client endpoint, as the same client handle may
210 * be used for both the owner and the destination, and
211 * we thus also need the channel ID to identify the client.
213 struct CadetClient *c;
216 * Head of DLL of messages received out of order or while client was unready.
218 struct CadetOutOfOrderMessage *head_recv;
221 * Tail DLL of messages received out of order or while client was unready.
223 struct CadetOutOfOrderMessage *tail_recv;
226 * Local tunnel number for this client.
227 * (if owner >= #GNUNET_CADET_LOCAL_CHANNEL_ID_CLI,
228 * otherwise < #GNUNET_CADET_LOCAL_CHANNEL_ID_CLI)
230 struct GNUNET_CADET_ClientChannelNumber ccn;
233 * Number of entries currently in @a head_recv DLL.
235 unsigned int num_recv;
238 * Can we send data to the client?
246 * Struct containing all information regarding a channel to a remote client.
251 * Tunnel this channel is in.
253 struct CadetTunnel *t;
256 * Client owner of the tunnel, if any.
257 * (Used if this channel represends the initiating end of the tunnel.)
259 struct CadetChannelClient *owner;
262 * Client destination of the tunnel, if any.
263 * (Used if this channel represents the listening end of the tunnel.)
265 struct CadetChannelClient *dest;
268 * Last entry in the tunnel's queue relating to control messages
269 * (#GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN or
270 * #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN_ACK). Used to cancel
271 * transmission in case we receive updated information.
273 struct CadetTunnelQueueEntry *last_control_qe;
276 * Head of DLL of messages sent and not yet ACK'd.
278 struct CadetReliableMessage *head_sent;
281 * Tail of DLL of messages sent and not yet ACK'd.
283 struct CadetReliableMessage *tail_sent;
286 * Task to resend/poll in case no ACK is received.
288 struct GNUNET_SCHEDULER_Task *retry_control_task;
291 * Task to resend/poll in case no ACK is received.
293 struct GNUNET_SCHEDULER_Task *retry_data_task;
296 * Last time the channel was used
298 struct GNUNET_TIME_Absolute timestamp;
301 * Destination port of the channel.
303 struct GNUNET_HashCode port;
306 * Hash'ed port of the channel with initiator and destination PID.
308 struct GNUNET_HashCode h_port;
311 * Counter for exponential backoff.
313 struct GNUNET_TIME_Relative retry_time;
316 * Bitfield of already-received messages past @e mid_recv.
318 uint64_t mid_futures;
321 * Next MID expected for incoming traffic.
323 struct ChannelMessageIdentifier mid_recv;
326 * Next MID to use for outgoing traffic.
328 struct ChannelMessageIdentifier mid_send;
331 * Total (reliable) messages pending ACK for this channel.
333 unsigned int pending_messages;
336 * Maximum (reliable) messages pending ACK for this channel
337 * before we throttle the client.
339 unsigned int max_pending_messages;
342 * Number identifying this channel in its tunnel.
344 struct GNUNET_CADET_ChannelTunnelNumber ctn;
349 enum CadetChannelState state;
352 * Count how many ACKs we skipped, used to prevent long
353 * sequences of ACK skipping.
355 unsigned int skip_ack_series;
358 * Is the tunnel bufferless (minimum latency)?
363 * Is the tunnel reliable?
368 * Is the tunnel out-of-order?
373 * Is this channel a loopback channel, where the destination is us again?
378 * Flag to signal the destruction of the channel. If this is set to
379 * #GNUNET_YES the channel will be destroyed once the queue is
388 * Get the static string for identification of the channel.
392 * @return Static string with the channel IDs.
395 GCCH_2s (const struct CadetChannel *ch)
397 static char buf[128];
399 GNUNET_snprintf (buf,
401 "Channel %s:%s ctn:%X(%X/%X)",
402 (GNUNET_YES == ch->is_loopback)
404 : GNUNET_i2s (GCP_get_id (GCT_get_destination (ch->t))),
405 GNUNET_h2s (&ch->port),
407 (NULL == ch->owner) ? 0 : ntohl (ch->owner->ccn.channel_of_client),
408 (NULL == ch->dest) ? 0 : ntohl (ch->dest->ccn.channel_of_client));
414 * Hash the @a port and @a initiator and @a listener to
415 * calculate the "challenge" @a h_port we send to the other
416 * peer on #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN.
418 * @param[out] h_port set to the hash of @a port, @a initiator and @a listener
419 * @param port cadet port, as seen by CADET clients
420 * @param listener peer that is listining on @a port
423 GCCH_hash_port (struct GNUNET_HashCode *h_port,
424 const struct GNUNET_HashCode *port,
425 const struct GNUNET_PeerIdentity *listener)
427 struct GNUNET_HashContext *hc;
429 hc = GNUNET_CRYPTO_hash_context_start ();
430 GNUNET_CRYPTO_hash_context_read (hc,
433 GNUNET_CRYPTO_hash_context_read (hc,
436 GNUNET_CRYPTO_hash_context_finish (hc,
438 LOG (GNUNET_ERROR_TYPE_DEBUG,
439 "Calculated port hash %s\n",
440 GNUNET_h2s (h_port));
445 * Get the channel's public ID.
449 * @return ID used to identify the channel with the remote peer.
451 struct GNUNET_CADET_ChannelTunnelNumber
452 GCCH_get_id (const struct CadetChannel *ch)
459 * Release memory associated with @a ccc
461 * @param ccc data structure to clean up
464 free_channel_client (struct CadetChannelClient *ccc)
466 struct CadetOutOfOrderMessage *com;
468 while (NULL != (com = ccc->head_recv))
470 GNUNET_CONTAINER_DLL_remove (ccc->head_recv,
474 GNUNET_MQ_discard (com->env);
482 * Destroy the given channel.
484 * @param ch channel to destroy
487 channel_destroy (struct CadetChannel *ch)
489 struct CadetReliableMessage *crm;
491 while (NULL != (crm = ch->head_sent))
493 GNUNET_assert (ch == crm->ch);
496 GCT_send_cancel (crm->qe);
499 GNUNET_CONTAINER_DLL_remove (ch->head_sent,
502 GNUNET_free (crm->data_message);
505 if (CADET_CHANNEL_LOOSE == ch->state)
507 GSC_drop_loose_channel (&ch->h_port,
510 if (NULL != ch->owner)
512 free_channel_client (ch->owner);
515 if (NULL != ch->dest)
517 free_channel_client (ch->dest);
520 if (NULL != ch->last_control_qe)
522 GCT_send_cancel (ch->last_control_qe);
523 ch->last_control_qe = NULL;
525 if (NULL != ch->retry_data_task)
527 GNUNET_SCHEDULER_cancel (ch->retry_data_task);
528 ch->retry_data_task = NULL;
530 if (NULL != ch->retry_control_task)
532 GNUNET_SCHEDULER_cancel (ch->retry_control_task);
533 ch->retry_control_task = NULL;
535 if (GNUNET_NO == ch->is_loopback)
537 GCT_remove_channel (ch->t,
547 * Send a channel create message.
549 * @param cls Channel for which to send.
552 send_channel_open (void *cls);
556 * Function called once the tunnel confirms that we sent the
557 * create message. Delays for a bit until we retry.
559 * @param cls our `struct CadetChannel`.
560 * @param cid identifier of the connection within the tunnel, NULL
561 * if transmission failed
564 channel_open_sent_cb (void *cls,
565 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid)
567 struct CadetChannel *ch = cls;
569 GNUNET_assert (NULL != ch->last_control_qe);
570 ch->last_control_qe = NULL;
571 ch->retry_time = GNUNET_TIME_STD_BACKOFF (ch->retry_time);
572 LOG (GNUNET_ERROR_TYPE_DEBUG,
573 "Sent CADET_CHANNEL_OPEN on %s, retrying in %s\n",
575 GNUNET_STRINGS_relative_time_to_string (ch->retry_time,
577 ch->retry_control_task
578 = GNUNET_SCHEDULER_add_delayed (ch->retry_time,
585 * Send a channel open message.
587 * @param cls Channel for which to send.
590 send_channel_open (void *cls)
592 struct CadetChannel *ch = cls;
593 struct GNUNET_CADET_ChannelOpenMessage msgcc;
595 ch->retry_control_task = NULL;
596 LOG (GNUNET_ERROR_TYPE_DEBUG,
597 "Sending CHANNEL_OPEN message for %s\n",
599 msgcc.header.size = htons (sizeof (msgcc));
600 msgcc.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN);
601 //TODO This will be removed in a major release, because this will be a protocol breaking change. We shift here to be compatible with GNUNET_CADET_OPTION_RELIABLE that was removed, and to already use the newly introduced options.
602 msgcc.opt = GNUNET_MQ_PREF_RELIABLE >> 10;
603 msgcc.h_port = ch->h_port;
605 ch->state = CADET_CHANNEL_OPEN_SENT;
606 if (NULL != ch->last_control_qe)
607 GCT_send_cancel (ch->last_control_qe);
608 ch->last_control_qe = GCT_send (ch->t,
610 &channel_open_sent_cb,
612 GNUNET_assert (NULL == ch->retry_control_task);
617 * Function called once and only once after a channel was bound
618 * to its tunnel via #GCT_add_channel() is ready for transmission.
619 * Note that this is only the case for channels that this peer
620 * initiates, as for incoming channels we assume that they are
621 * ready for transmission immediately upon receiving the open
622 * message. Used to bootstrap the #GCT_send() process.
624 * @param ch the channel for which the tunnel is now ready
627 GCCH_tunnel_up (struct CadetChannel *ch)
629 GNUNET_assert (NULL == ch->retry_control_task);
630 LOG (GNUNET_ERROR_TYPE_DEBUG,
631 "Tunnel up, sending CHANNEL_OPEN on %s now\n",
633 ch->retry_control_task
634 = GNUNET_SCHEDULER_add_now (&send_channel_open,
640 * Create a new channel.
642 * @param owner local client owning the channel
643 * @param ccn local number of this channel at the @a owner
644 * @param destination peer to which we should build the channel
645 * @param port desired port at @a destination
646 * @param options options for the channel
647 * @return handle to the new channel
649 struct CadetChannel *
650 GCCH_channel_local_new (struct CadetClient *owner,
651 struct GNUNET_CADET_ClientChannelNumber ccn,
652 struct CadetPeer *destination,
653 const struct GNUNET_HashCode *port,
656 struct CadetChannel *ch;
657 struct CadetChannelClient *ccco;
659 ccco = GNUNET_new (struct CadetChannelClient);
662 ccco->client_ready = GNUNET_YES;
664 ch = GNUNET_new (struct CadetChannel);
665 ch->mid_recv.mid = htonl (1); /* The OPEN_ACK counts as message 0! */
666 ch->nobuffer = GNUNET_NO ;
667 ch->reliable = GNUNET_YES;
668 ch->out_of_order = GNUNET_NO ;
669 ch->max_pending_messages = (ch->nobuffer) ? 1 : 4; /* FIXME: 4!? Do not hardcode! */
672 GCCH_hash_port (&ch->h_port,
674 GCP_get_id (destination));
675 if (0 == GNUNET_memcmp (&my_full_id,
676 GCP_get_id (destination)))
680 ch->is_loopback = GNUNET_YES;
681 op = GNUNET_CONTAINER_multihashmap_get (open_ports,
685 /* port closed, wait for it to possibly open */
686 ch->state = CADET_CHANNEL_LOOSE;
687 (void) GNUNET_CONTAINER_multihashmap_put (loose_channels,
690 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
691 LOG (GNUNET_ERROR_TYPE_DEBUG,
692 "Created loose incoming loopback channel to port %s\n",
693 GNUNET_h2s (&ch->port));
704 ch->t = GCP_get_tunnel (destination,
706 ch->retry_time = CADET_INITIAL_RETRANSMIT_TIME;
707 ch->ctn = GCT_add_channel (ch->t,
710 GNUNET_STATISTICS_update (stats,
714 LOG (GNUNET_ERROR_TYPE_DEBUG,
715 "Created channel to port %s at peer %s for %s using %s\n",
717 GCP_2s (destination),
719 (GNUNET_YES == ch->is_loopback) ? "loopback" : GCT_2s (ch->t));
725 * We had an incoming channel to a port that is closed.
726 * It has not been opened for a while, drop it.
728 * @param cls the channel to drop
731 timeout_closed_cb (void *cls)
733 struct CadetChannel *ch = cls;
735 ch->retry_control_task = NULL;
736 LOG (GNUNET_ERROR_TYPE_DEBUG,
737 "Closing incoming channel to port %s from peer %s due to timeout\n",
738 GNUNET_h2s (&ch->port),
739 GCP_2s (GCT_get_destination (ch->t)));
740 channel_destroy (ch);
745 * Create a new channel based on a request coming in over the network.
747 * @param t tunnel to the remote peer
748 * @param ctn identifier of this channel in the tunnel
749 * @param h_port desired hash of local port
750 * @param options options for the channel
751 * @return handle to the new channel
753 struct CadetChannel *
754 GCCH_channel_incoming_new (struct CadetTunnel *t,
755 struct GNUNET_CADET_ChannelTunnelNumber ctn,
756 const struct GNUNET_HashCode *h_port,
759 struct CadetChannel *ch;
762 ch = GNUNET_new (struct CadetChannel);
763 ch->h_port = *h_port;
766 ch->retry_time = CADET_INITIAL_RETRANSMIT_TIME;
767 ch->nobuffer = GNUNET_NO;
768 ch->reliable = GNUNET_YES;
769 ch->out_of_order = GNUNET_NO;
770 ch->max_pending_messages = (ch->nobuffer) ? 1 : 4; /* FIXME: 4!? Do not hardcode! */
771 GNUNET_STATISTICS_update (stats,
776 op = GNUNET_CONTAINER_multihashmap_get (open_ports,
780 /* port closed, wait for it to possibly open */
781 ch->state = CADET_CHANNEL_LOOSE;
782 (void) GNUNET_CONTAINER_multihashmap_put (loose_channels,
785 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
786 GNUNET_assert (NULL == ch->retry_control_task);
787 ch->retry_control_task
788 = GNUNET_SCHEDULER_add_delayed (TIMEOUT_CLOSED_PORT,
791 LOG (GNUNET_ERROR_TYPE_DEBUG,
792 "Created loose incoming channel to port %s from peer %s\n",
793 GNUNET_h2s (&ch->port),
794 GCP_2s (GCT_get_destination (ch->t)));
802 GNUNET_STATISTICS_update (stats,
811 * Function called once the tunnel confirms that we sent the
812 * ACK message. Just remembers it was sent, we do not expect
815 * @param cls our `struct CadetChannel`.
816 * @param cid identifier of the connection within the tunnel, NULL
817 * if transmission failed
820 send_ack_cb (void *cls,
821 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid)
823 struct CadetChannel *ch = cls;
825 GNUNET_assert (NULL != ch->last_control_qe);
826 ch->last_control_qe = NULL;
831 * Compute and send the current #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA_ACK to the other peer.
833 * @param ch channel to send the #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA_ACK for
836 send_channel_data_ack (struct CadetChannel *ch)
838 struct GNUNET_CADET_ChannelDataAckMessage msg;
840 if (GNUNET_NO == ch->reliable)
841 return; /* no ACKs */
842 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA_ACK);
843 msg.header.size = htons (sizeof (msg));
845 msg.mid.mid = htonl (ntohl (ch->mid_recv.mid));
846 msg.futures = GNUNET_htonll (ch->mid_futures);
847 LOG (GNUNET_ERROR_TYPE_DEBUG,
848 "Sending DATA_ACK %u:%llX via %s\n",
849 (unsigned int) ntohl (msg.mid.mid),
850 (unsigned long long) ch->mid_futures,
852 if (NULL != ch->last_control_qe)
853 GCT_send_cancel (ch->last_control_qe);
854 ch->last_control_qe = GCT_send (ch->t,
862 * Send our initial #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN_ACK to the client confirming that the
865 * @param cls the `struct CadetChannel`
868 send_open_ack (void *cls)
870 struct CadetChannel *ch = cls;
871 struct GNUNET_CADET_ChannelOpenAckMessage msg;
873 ch->retry_control_task = NULL;
874 LOG (GNUNET_ERROR_TYPE_DEBUG,
875 "Sending CHANNEL_OPEN_ACK on %s\n",
877 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN_ACK);
878 msg.header.size = htons (sizeof (msg));
879 msg.reserved = htonl (0);
882 if (NULL != ch->last_control_qe)
883 GCT_send_cancel (ch->last_control_qe);
884 ch->last_control_qe = GCT_send (ch->t,
892 * We got a #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN message again for
893 * this channel. If the binding was successful, (re)transmit the
894 * #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN_ACK.
896 * @param ch channel that got the duplicate open
897 * @param cti identifier of the connection that delivered the message
900 GCCH_handle_duplicate_open (struct CadetChannel *ch,
901 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti)
903 if (NULL == ch->dest)
905 LOG (GNUNET_ERROR_TYPE_DEBUG,
906 "Ignoring duplicate CHANNEL_OPEN on %s: port is closed\n",
910 if (NULL != ch->retry_control_task)
912 LOG (GNUNET_ERROR_TYPE_DEBUG,
913 "Ignoring duplicate CHANNEL_OPEN on %s: control message is pending\n",
917 LOG (GNUNET_ERROR_TYPE_DEBUG,
918 "Retransmitting CHANNEL_OPEN_ACK on %s\n",
920 ch->retry_control_task
921 = GNUNET_SCHEDULER_add_now (&send_open_ack,
927 * Send a #GNUNET_MESSAGE_TYPE_CADET_LOCAL_ACK to the client to solicit more messages.
929 * @param ch channel the ack is for
930 * @param to_owner #GNUNET_YES to send to owner,
931 * #GNUNET_NO to send to dest
934 send_ack_to_client (struct CadetChannel *ch,
937 struct GNUNET_MQ_Envelope *env;
938 struct GNUNET_CADET_LocalAck *ack;
939 struct CadetChannelClient *ccc;
941 ccc = (GNUNET_YES == to_owner) ? ch->owner : ch->dest;
944 /* This can happen if we are just getting ACKs after
945 our local client already disconnected. */
946 GNUNET_assert (GNUNET_YES == ch->destroy);
949 env = GNUNET_MQ_msg (ack,
950 GNUNET_MESSAGE_TYPE_CADET_LOCAL_ACK);
952 LOG (GNUNET_ERROR_TYPE_DEBUG,
953 "Sending CADET_LOCAL_ACK to %s (%s) at ccn %X (%u/%u pending)\n",
955 (GNUNET_YES == to_owner) ? "owner" : "dest",
956 ntohl (ack->ccn.channel_of_client),
957 ch->pending_messages,
958 ch->max_pending_messages);
959 GSC_send_to_client (ccc->c,
965 * A client is bound to the port that we have a channel
966 * open to. Send the acknowledgement for the connection
967 * request and establish the link with the client.
969 * @param ch open incoming channel
970 * @param c client listening on the respective @a port
971 * @param port the port @a is listening on
974 GCCH_bind (struct CadetChannel *ch,
975 struct CadetClient *c,
976 const struct GNUNET_HashCode *port)
979 struct CadetChannelClient *cccd;
981 LOG (GNUNET_ERROR_TYPE_DEBUG,
982 "Binding %s from %s to port %s of %s\n",
985 GNUNET_h2s (&ch->port),
987 if (NULL != ch->retry_control_task)
989 /* there might be a timeout task here */
990 GNUNET_SCHEDULER_cancel (ch->retry_control_task);
991 ch->retry_control_task = NULL;
994 cccd = GNUNET_new (struct CadetChannelClient);
995 GNUNET_assert (NULL == ch->dest);
999 cccd->client_ready = GNUNET_YES;
1000 cccd->ccn = GSC_bind (c,
1002 (GNUNET_YES == ch->is_loopback)
1003 ? GCP_get (&my_full_id,
1005 : GCT_get_destination (ch->t),
1008 GNUNET_assert (ntohl (cccd->ccn.channel_of_client) <
1009 GNUNET_CADET_LOCAL_CHANNEL_ID_CLI);
1010 ch->mid_recv.mid = htonl (1); /* The OPEN counts as message 0! */
1011 if (GNUNET_YES == ch->is_loopback)
1013 ch->state = CADET_CHANNEL_OPEN_SENT;
1014 GCCH_handle_channel_open_ack (ch,
1020 /* notify other peer that we accepted the connection */
1021 ch->state = CADET_CHANNEL_READY;
1022 ch->retry_control_task
1023 = GNUNET_SCHEDULER_add_now (&send_open_ack,
1026 /* give client it's initial supply of ACKs */
1027 GNUNET_assert (ntohl (cccd->ccn.channel_of_client) <
1028 GNUNET_CADET_LOCAL_CHANNEL_ID_CLI);
1029 for (unsigned int i=0;i<ch->max_pending_messages;i++)
1030 send_ack_to_client (ch,
1036 * One of our clients has disconnected, tell the other one that we
1037 * are finished. Done asynchronously to avoid concurrent modification
1038 * issues if this is the same client.
1040 * @param cls the `struct CadetChannel` where one of the ends is now dead
1043 signal_remote_destroy_cb (void *cls)
1045 struct CadetChannel *ch = cls;
1046 struct CadetChannelClient *ccc;
1048 /* Find which end is left... */
1049 ch->retry_control_task = NULL;
1050 ccc = (NULL != ch->owner) ? ch->owner : ch->dest;
1051 GSC_handle_remote_channel_destroy (ccc->c,
1054 channel_destroy (ch);
1059 * Destroy locally created channel. Called by the local client, so no
1060 * need to tell the client.
1062 * @param ch channel to destroy
1063 * @param c client that caused the destruction
1064 * @param ccn client number of the client @a c
1067 GCCH_channel_local_destroy (struct CadetChannel *ch,
1068 struct CadetClient *c,
1069 struct GNUNET_CADET_ClientChannelNumber ccn)
1071 LOG (GNUNET_ERROR_TYPE_DEBUG,
1072 "%s asks for destruction of %s\n",
1075 GNUNET_assert (NULL != c);
1076 if ( (NULL != ch->owner) &&
1077 (c == ch->owner->c) &&
1078 (ccn.channel_of_client == ch->owner->ccn.channel_of_client) )
1080 free_channel_client (ch->owner);
1083 else if ( (NULL != ch->dest) &&
1084 (c == ch->dest->c) &&
1085 (ccn.channel_of_client == ch->dest->ccn.channel_of_client) )
1087 free_channel_client (ch->dest);
1095 if (GNUNET_YES == ch->destroy)
1097 /* other end already destroyed, with the local client gone, no need
1098 to finish transmissions, just destroy immediately. */
1099 channel_destroy (ch);
1102 if ( (NULL != ch->head_sent) &&
1103 ( (NULL != ch->owner) ||
1104 (NULL != ch->dest) ) )
1106 /* Wait for other end to destroy us as well,
1107 and otherwise allow send queue to be transmitted first */
1108 ch->destroy = GNUNET_YES;
1111 if ( (GNUNET_YES == ch->is_loopback) &&
1112 ( (NULL != ch->owner) ||
1113 (NULL != ch->dest) ) )
1115 if (NULL != ch->retry_control_task)
1116 GNUNET_SCHEDULER_cancel (ch->retry_control_task);
1117 ch->retry_control_task
1118 = GNUNET_SCHEDULER_add_now (&signal_remote_destroy_cb,
1122 if (GNUNET_NO == ch->is_loopback)
1124 /* If the we ever sent the CHANNEL_CREATE, we need to send a destroy message. */
1127 case CADET_CHANNEL_NEW:
1128 /* We gave up on a channel that we created as a client to a remote
1129 target, but that never went anywhere. Nothing to do here. */
1131 case CADET_CHANNEL_LOOSE:
1134 GCT_send_channel_destroy (ch->t,
1138 /* Nothing left to do, just finish destruction */
1139 channel_destroy (ch);
1144 * We got an acknowledgement for the creation of the channel
1145 * (the port is open on the other side). Verify that the
1146 * other end really has the right port, and begin transmissions.
1148 * @param ch channel to destroy
1149 * @param cti identifier of the connection that delivered the message
1150 * @param port port number (needed to verify receiver knows the port)
1153 GCCH_handle_channel_open_ack (struct CadetChannel *ch,
1154 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti,
1155 const struct GNUNET_HashCode *port)
1159 case CADET_CHANNEL_NEW:
1160 /* this should be impossible */
1163 case CADET_CHANNEL_LOOSE:
1164 /* This makes no sense. */
1165 GNUNET_break_op (0);
1167 case CADET_CHANNEL_OPEN_SENT:
1168 if (NULL == ch->owner)
1170 /* We're not the owner, wrong direction! */
1171 GNUNET_break_op (0);
1174 if (0 != GNUNET_memcmp (&ch->port,
1177 /* Other peer failed to provide the right port,
1178 refuse connection. */
1179 GNUNET_break_op (0);
1182 LOG (GNUNET_ERROR_TYPE_DEBUG,
1183 "Received CHANNEL_OPEN_ACK for waiting %s, entering READY state\n",
1185 if (NULL != ch->retry_control_task) /* can be NULL if ch->is_loopback */
1187 GNUNET_SCHEDULER_cancel (ch->retry_control_task);
1188 ch->retry_control_task = NULL;
1190 ch->state = CADET_CHANNEL_READY;
1191 /* On first connect, send client as many ACKs as we allow messages
1193 for (unsigned int i=0;i<ch->max_pending_messages;i++)
1194 send_ack_to_client (ch,
1197 case CADET_CHANNEL_READY:
1198 /* duplicate ACK, maybe we retried the CREATE. Ignore. */
1199 LOG (GNUNET_ERROR_TYPE_DEBUG,
1200 "Received duplicate channel OPEN_ACK for %s\n",
1202 GNUNET_STATISTICS_update (stats,
1203 "# duplicate CREATE_ACKs",
1212 * Test if element @a e1 comes before element @a e2.
1214 * @param cls closure, to a flag where we indicate duplicate packets
1215 * @param m1 a message of to sort
1216 * @param m2 another message to sort
1217 * @return #GNUNET_YES if @e1 < @e2, otherwise #GNUNET_NO
1220 is_before (void *cls,
1221 struct CadetOutOfOrderMessage *m1,
1222 struct CadetOutOfOrderMessage *m2)
1224 int *duplicate = cls;
1225 uint32_t v1 = ntohl (m1->mid.mid);
1226 uint32_t v2 = ntohl (m2->mid.mid);
1231 *duplicate = GNUNET_YES;
1232 if (delta > (uint32_t) INT_MAX)
1234 /* in overflow range, we can safely assume we wrapped around */
1239 /* result is small, thus v2 > v1, thus m1 < m2 */
1246 * We got payload data for a channel. Pass it on to the client
1247 * and send an ACK to the other end (once flow control allows it!)
1249 * @param ch channel that got data
1250 * @param cti identifier of the connection that delivered the message
1251 * @param msg message that was received
1254 GCCH_handle_channel_plaintext_data (struct CadetChannel *ch,
1255 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti,
1256 const struct GNUNET_CADET_ChannelAppDataMessage *msg)
1258 struct GNUNET_MQ_Envelope *env;
1259 struct GNUNET_CADET_LocalData *ld;
1260 struct CadetChannelClient *ccc;
1261 size_t payload_size;
1262 struct CadetOutOfOrderMessage *com;
1269 GNUNET_assert (GNUNET_NO == ch->is_loopback);
1270 if ( (NULL == ch->owner) &&
1271 (NULL == ch->dest) )
1273 /* This client is gone, but we still have messages to send to
1274 the other end (which is why @a ch is not yet dead). However,
1275 we cannot pass messages to our client anymore. */
1276 LOG (GNUNET_ERROR_TYPE_DEBUG,
1277 "Dropping incoming payload on %s as this end is already closed\n",
1279 /* send back DESTROY notification to stop further retransmissions! */
1280 if (GNUNET_YES == ch->destroy)
1281 GCT_send_channel_destroy (ch->t,
1285 payload_size = ntohs (msg->header.size) - sizeof (*msg);
1286 env = GNUNET_MQ_msg_extra (ld,
1288 GNUNET_MESSAGE_TYPE_CADET_LOCAL_DATA);
1289 ld->ccn = (NULL == ch->dest) ? ch->owner->ccn : ch->dest->ccn;
1290 GNUNET_memcpy (&ld[1],
1293 ccc = (NULL != ch->owner) ? ch->owner : ch->dest;
1294 if (GNUNET_YES == ccc->client_ready)
1297 * We ad-hoc send the message if
1298 * - The channel is out-of-order
1299 * - The channel is reliable and MID matches next expected MID
1300 * - The channel is unreliable and MID is before lowest seen MID
1302 if ( (GNUNET_YES == ch->out_of_order) ||
1303 ((msg->mid.mid == ch->mid_recv.mid) &&
1304 (GNUNET_YES == ch->reliable)) ||
1305 ((GNUNET_NO == ch->reliable) &&
1306 (ntohl (msg->mid.mid) >= ntohl (ch->mid_recv.mid)) &&
1307 ((NULL == ccc->head_recv) ||
1308 (ntohl (msg->mid.mid) < ntohl (ccc->head_recv->mid.mid)))) )
1310 LOG (GNUNET_ERROR_TYPE_DEBUG,
1311 "Giving %u bytes of payload with MID %u from %s to client %s\n",
1312 (unsigned int) payload_size,
1313 ntohl (msg->mid.mid),
1316 ccc->client_ready = GNUNET_NO;
1317 GSC_send_to_client (ccc->c,
1319 if (GNUNET_NO == ch->out_of_order)
1320 ch->mid_recv.mid = htonl (1 + ntohl (msg->mid.mid));
1322 ch->mid_recv.mid = htonl (1 + ntohl (ch->mid_recv.mid));
1323 ch->mid_futures >>= 1;
1324 if ( (GNUNET_YES == ch->out_of_order) &&
1325 (GNUNET_NO == ch->reliable) )
1327 /* possibly shift by more if we skipped messages */
1328 uint64_t delta = htonl (msg->mid.mid) - 1 - ntohl (ch->mid_recv.mid);
1331 ch->mid_futures = 0;
1333 ch->mid_futures >>= delta;
1334 ch->mid_recv.mid = htonl (1 + ntohl (msg->mid.mid));
1336 send_channel_data_ack (ch);
1341 if (GNUNET_YES == ch->reliable)
1343 /* check if message ought to be dropped because it is ancient/too distant/duplicate */
1344 mid_min = ntohl (ch->mid_recv.mid);
1345 mid_max = mid_min + ch->max_pending_messages;
1346 mid_msg = ntohl (msg->mid.mid);
1347 if ( ( (uint32_t) (mid_msg - mid_min) > ch->max_pending_messages) ||
1348 ( (uint32_t) (mid_max - mid_msg) > ch->max_pending_messages) )
1350 LOG (GNUNET_ERROR_TYPE_DEBUG,
1351 "%s at %u drops ancient or far-future message %u\n",
1353 (unsigned int) mid_min,
1354 ntohl (msg->mid.mid));
1356 GNUNET_STATISTICS_update (stats,
1357 "# duplicate DATA (ancient or future)",
1360 GNUNET_MQ_discard (env);
1361 send_channel_data_ack (ch);
1364 /* mark bit for future ACKs */
1365 delta = mid_msg - mid_min - 1; /* overflow/underflow are OK here */
1368 if (0 != (ch->mid_futures & (1LLU << delta)))
1370 /* Duplicate within the queue, drop also */
1371 LOG (GNUNET_ERROR_TYPE_DEBUG,
1372 "Duplicate payload of %u bytes on %s (mid %u) dropped\n",
1373 (unsigned int) payload_size,
1375 ntohl (msg->mid.mid));
1376 GNUNET_STATISTICS_update (stats,
1380 GNUNET_MQ_discard (env);
1381 send_channel_data_ack (ch);
1384 ch->mid_futures |= (1LLU << delta);
1385 LOG (GNUNET_ERROR_TYPE_DEBUG,
1386 "Marked bit %llX for mid %u (base: %u); now: %llX\n",
1393 else /* ! ch->reliable */
1395 struct CadetOutOfOrderMessage *next_msg;
1398 * We always send if possible in this case.
1399 * It is guaranteed that the queued MID < received MID
1401 if ((NULL != ccc->head_recv) &&
1402 (GNUNET_YES == ccc->client_ready))
1404 next_msg = ccc->head_recv;
1405 LOG (GNUNET_ERROR_TYPE_DEBUG,
1406 "Giving queued MID %u from %s to client %s\n",
1407 ntohl (next_msg->mid.mid),
1410 ccc->client_ready = GNUNET_NO;
1411 GSC_send_to_client (ccc->c,
1413 ch->mid_recv.mid = htonl (1 + ntohl (next_msg->mid.mid));
1414 ch->mid_futures >>= 1;
1415 send_channel_data_ack (ch);
1416 GNUNET_CONTAINER_DLL_remove (ccc->head_recv,
1420 /* Do not process duplicate MID */
1421 if (msg->mid.mid == next_msg->mid.mid) /* Duplicate */
1423 /* Duplicate within the queue, drop */
1424 LOG (GNUNET_ERROR_TYPE_DEBUG,
1425 "Message on %s (mid %u) dropped, duplicate\n",
1427 ntohl (msg->mid.mid));
1428 GNUNET_free (next_msg);
1429 GNUNET_MQ_discard (env);
1432 GNUNET_free (next_msg);
1435 if (ntohl (msg->mid.mid) < ntohl (ch->mid_recv.mid)) /* Old */
1437 /* Duplicate within the queue, drop */
1438 LOG (GNUNET_ERROR_TYPE_DEBUG,
1439 "Message on %s (mid %u) dropped, old.\n",
1441 ntohl (msg->mid.mid));
1442 GNUNET_MQ_discard (env);
1446 /* Channel is unreliable, so we do not ACK. But we also cannot
1447 allow buffering everything, so check if we have space... */
1448 if (ccc->num_recv >= ch->max_pending_messages)
1450 struct CadetOutOfOrderMessage *drop;
1452 /* Yep, need to drop. Drop the oldest message in
1454 LOG (GNUNET_ERROR_TYPE_DEBUG,
1455 "Queue full due slow client on %s, dropping oldest message\n",
1457 GNUNET_STATISTICS_update (stats,
1458 "# messages dropped due to slow client",
1461 drop = ccc->head_recv;
1462 GNUNET_assert (NULL != drop);
1463 GNUNET_CONTAINER_DLL_remove (ccc->head_recv,
1467 GNUNET_MQ_discard (drop->env);
1472 /* Insert message into sorted out-of-order queue */
1473 com = GNUNET_new (struct CadetOutOfOrderMessage);
1474 com->mid = msg->mid;
1476 duplicate = GNUNET_NO;
1477 GNUNET_CONTAINER_DLL_insert_sorted (struct CadetOutOfOrderMessage,
1484 if (GNUNET_YES == duplicate)
1486 /* Duplicate within the queue, drop also (this is not covered by
1487 the case above if "delta" >= 64, which could be the case if
1488 max_pending_messages is also >= 64 or if our client is unready
1489 and we are seeing retransmissions of the message our client is
1491 LOG (GNUNET_ERROR_TYPE_DEBUG,
1492 "Duplicate payload of %u bytes on %s (mid %u) dropped\n",
1493 (unsigned int) payload_size,
1495 ntohl (msg->mid.mid));
1496 GNUNET_STATISTICS_update (stats,
1500 GNUNET_CONTAINER_DLL_remove (ccc->head_recv,
1504 GNUNET_MQ_discard (com->env);
1506 send_channel_data_ack (ch);
1509 LOG (GNUNET_ERROR_TYPE_DEBUG,
1510 "Queued %s payload of %u bytes on %s-%X(%p) (mid %u, need %u first)\n",
1511 (GNUNET_YES == ccc->client_ready)
1513 : "client-not-ready",
1514 (unsigned int) payload_size,
1516 ntohl (ccc->ccn.channel_of_client),
1518 ntohl (msg->mid.mid),
1519 ntohl (ch->mid_recv.mid));
1520 /* NOTE: this ACK we _could_ skip, as the packet is out-of-order and
1521 the sender may already be transmitting the previous one. Needs
1522 experimental evaluation to see if/when this ACK helps or
1523 hurts. (We might even want another option.) */
1524 send_channel_data_ack (ch);
1529 * Function called once the tunnel has sent one of our messages.
1530 * If the message is unreliable, simply frees the `crm`. If the
1531 * message was reliable, calculate retransmission time and
1532 * wait for ACK (or retransmit).
1534 * @param cls the `struct CadetReliableMessage` that was sent
1535 * @param cid identifier of the connection within the tunnel, NULL
1536 * if transmission failed
1539 data_sent_cb (void *cls,
1540 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid);
1544 * We need to retry a transmission, the last one took too long to
1547 * @param cls the `struct CadetChannel` where we need to retransmit
1550 retry_transmission (void *cls)
1552 struct CadetChannel *ch = cls;
1553 struct CadetReliableMessage *crm = ch->head_sent;
1555 ch->retry_data_task = NULL;
1556 GNUNET_assert (NULL == crm->qe);
1557 LOG (GNUNET_ERROR_TYPE_DEBUG,
1558 "Retrying transmission on %s of message %u\n",
1560 (unsigned int) ntohl (crm->data_message->mid.mid));
1561 crm->qe = GCT_send (ch->t,
1562 &crm->data_message->header,
1565 GNUNET_assert (NULL == ch->retry_data_task);
1570 * We got an PLAINTEXT_DATA_ACK for a message in our queue, remove it from
1571 * the queue and tell our client that it can send more.
1573 * @param ch the channel that got the PLAINTEXT_DATA_ACK
1574 * @param cti identifier of the connection that delivered the message
1575 * @param crm the message that got acknowledged
1578 handle_matching_ack (struct CadetChannel *ch,
1579 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti,
1580 struct CadetReliableMessage *crm)
1582 GNUNET_CONTAINER_DLL_remove (ch->head_sent,
1585 ch->pending_messages--;
1586 GNUNET_assert (ch->pending_messages < ch->max_pending_messages);
1587 LOG (GNUNET_ERROR_TYPE_DEBUG,
1588 "Received DATA_ACK on %s for message %u (%u ACKs pending)\n",
1590 (unsigned int) ntohl (crm->data_message->mid.mid),
1591 ch->pending_messages);
1592 if (NULL != crm->qe)
1594 GCT_send_cancel (crm->qe);
1597 if ( (1 == crm->num_transmissions) &&
1600 GCC_ack_observed (cti);
1601 if (0 == GNUNET_memcmp (cti,
1602 &crm->connection_taken))
1604 GCC_latency_observed (cti,
1605 GNUNET_TIME_absolute_get_duration (crm->first_transmission_time));
1608 GNUNET_free (crm->data_message);
1610 send_ack_to_client (ch,
1618 * We got an acknowledgement for payload data for a channel.
1619 * Possibly resume transmissions.
1621 * @param ch channel that got the ack
1622 * @param cti identifier of the connection that delivered the message
1623 * @param ack details about what was received
1626 GCCH_handle_channel_plaintext_data_ack (struct CadetChannel *ch,
1627 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti,
1628 const struct GNUNET_CADET_ChannelDataAckMessage *ack)
1630 struct CadetReliableMessage *crm;
1631 struct CadetReliableMessage *crmn;
1637 GNUNET_break (GNUNET_NO == ch->is_loopback);
1638 if (GNUNET_NO == ch->reliable)
1640 /* not expecting ACKs on unreliable channel, odd */
1641 GNUNET_break_op (0);
1644 /* mid_base is the MID of the next message that the
1645 other peer expects (i.e. that is missing!), everything
1646 LOWER (but excluding mid_base itself) was received. */
1647 mid_base = ntohl (ack->mid.mid);
1648 mid_mask = GNUNET_htonll (ack->futures);
1650 for (crm = ch->head_sent;
1655 delta = (unsigned int) (ntohl (crm->data_message->mid.mid) - mid_base);
1656 if (delta >= UINT_MAX - ch->max_pending_messages)
1658 /* overflow, means crm was a bit in the past, so this ACK counts for it. */
1659 LOG (GNUNET_ERROR_TYPE_DEBUG,
1660 "Got DATA_ACK with base %u satisfying past message %u on %s\n",
1661 (unsigned int) mid_base,
1662 ntohl (crm->data_message->mid.mid),
1664 handle_matching_ack (ch,
1673 LOG (GNUNET_ERROR_TYPE_DEBUG,
1674 "Testing bit %llX for mid %u (base: %u)\n",
1676 ntohl (crm->data_message->mid.mid),
1678 if (0 != (mid_mask & (1LLU << delta)))
1680 LOG (GNUNET_ERROR_TYPE_DEBUG,
1681 "Got DATA_ACK with mask for %u on %s\n",
1682 ntohl (crm->data_message->mid.mid),
1684 handle_matching_ack (ch,
1690 if (GNUNET_NO == found)
1692 /* ACK for message we already dropped, might have been a
1693 duplicate ACK? Ignore. */
1694 LOG (GNUNET_ERROR_TYPE_DEBUG,
1695 "Duplicate DATA_ACK on %s, ignoring\n",
1697 GNUNET_STATISTICS_update (stats,
1698 "# duplicate DATA_ACKs",
1703 if (NULL != ch->retry_data_task)
1705 GNUNET_SCHEDULER_cancel (ch->retry_data_task);
1706 ch->retry_data_task = NULL;
1708 if ( (NULL != ch->head_sent) &&
1709 (NULL == ch->head_sent->qe) )
1711 = GNUNET_SCHEDULER_add_at (ch->head_sent->next_retry,
1712 &retry_transmission,
1718 * Destroy channel, based on the other peer closing the
1719 * connection. Also needs to remove this channel from
1722 * @param ch channel to destroy
1723 * @param cti identifier of the connection that delivered the message,
1724 * NULL if we are simulating receiving a destroy due to shutdown
1727 GCCH_handle_remote_destroy (struct CadetChannel *ch,
1728 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti)
1730 struct CadetChannelClient *ccc;
1732 GNUNET_assert (GNUNET_NO == ch->is_loopback);
1733 LOG (GNUNET_ERROR_TYPE_DEBUG,
1734 "Received remote channel DESTROY for %s\n",
1736 if (GNUNET_YES == ch->destroy)
1738 /* Local client already gone, this is instant-death. */
1739 channel_destroy (ch);
1742 ccc = (NULL != ch->owner) ? ch->owner : ch->dest;
1743 if ( (NULL != ccc) &&
1744 (NULL != ccc->head_recv) )
1746 LOG (GNUNET_ERROR_TYPE_WARNING,
1747 "Lost end of transmission due to remote shutdown on %s\n",
1749 /* FIXME: change API to notify client about truncated transmission! */
1751 ch->destroy = GNUNET_YES;
1753 GSC_handle_remote_channel_destroy (ccc->c,
1756 channel_destroy (ch);
1761 * Test if element @a e1 comes before element @a e2.
1763 * @param cls closure, to a flag where we indicate duplicate packets
1764 * @param crm1 an element of to sort
1765 * @param crm2 another element to sort
1766 * @return #GNUNET_YES if @e1 < @e2, otherwise #GNUNET_NO
1769 cmp_crm_by_next_retry (void *cls,
1770 struct CadetReliableMessage *crm1,
1771 struct CadetReliableMessage *crm2)
1773 if (crm1->next_retry.abs_value_us <
1774 crm2->next_retry.abs_value_us)
1781 * Function called once the tunnel has sent one of our messages.
1782 * If the message is unreliable, simply frees the `crm`. If the
1783 * message was reliable, calculate retransmission time and
1784 * wait for ACK (or retransmit).
1786 * @param cls the `struct CadetReliableMessage` that was sent
1787 * @param cid identifier of the connection within the tunnel, NULL
1788 * if transmission failed
1791 data_sent_cb (void *cls,
1792 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid)
1794 struct CadetReliableMessage *crm = cls;
1795 struct CadetChannel *ch = crm->ch;
1797 GNUNET_assert (GNUNET_NO == ch->is_loopback);
1798 GNUNET_assert (NULL != crm->qe);
1800 GNUNET_CONTAINER_DLL_remove (ch->head_sent,
1803 if (GNUNET_NO == ch->reliable)
1805 GNUNET_free (crm->data_message);
1807 ch->pending_messages--;
1808 send_ack_to_client (ch,
1816 /* There was an error sending. */
1817 crm->num_transmissions = GNUNET_SYSERR;
1819 else if (GNUNET_SYSERR != crm->num_transmissions)
1821 /* Increment transmission counter, and possibly store @a cid
1822 if this was the first transmission. */
1823 crm->num_transmissions++;
1824 if (1 == crm->num_transmissions)
1826 crm->first_transmission_time = GNUNET_TIME_absolute_get ();
1827 crm->connection_taken = *cid;
1828 GCC_ack_expected (cid);
1831 if ( (0 == crm->retry_delay.rel_value_us) &&
1834 struct CadetConnection *cc = GCC_lookup (cid);
1837 crm->retry_delay = GCC_get_metrics (cc)->aged_latency;
1839 crm->retry_delay = ch->retry_time;
1841 crm->retry_delay = GNUNET_TIME_STD_BACKOFF (crm->retry_delay);
1842 crm->retry_delay = GNUNET_TIME_relative_max (crm->retry_delay,
1844 crm->next_retry = GNUNET_TIME_relative_to_absolute (crm->retry_delay);
1846 GNUNET_CONTAINER_DLL_insert_sorted (struct CadetReliableMessage,
1847 cmp_crm_by_next_retry,
1852 LOG (GNUNET_ERROR_TYPE_DEBUG,
1853 "Message %u sent, next transmission on %s in %s\n",
1854 (unsigned int) ntohl (crm->data_message->mid.mid),
1856 GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_remaining (ch->head_sent->next_retry),
1858 if (NULL == ch->head_sent->qe)
1860 if (NULL != ch->retry_data_task)
1861 GNUNET_SCHEDULER_cancel (ch->retry_data_task);
1863 = GNUNET_SCHEDULER_add_at (ch->head_sent->next_retry,
1864 &retry_transmission,
1871 * Handle data given by a client.
1873 * Check whether the client is allowed to send in this tunnel, save if
1874 * channel is reliable and send an ACK to the client if there is still
1875 * buffer space in the tunnel.
1877 * @param ch Channel.
1878 * @param sender_ccn ccn of the sender
1879 * @param buf payload to transmit.
1880 * @param buf_len number of bytes in @a buf
1881 * @return #GNUNET_OK if everything goes well,
1882 * #GNUNET_SYSERR in case of an error.
1885 GCCH_handle_local_data (struct CadetChannel *ch,
1886 struct GNUNET_CADET_ClientChannelNumber sender_ccn,
1890 struct CadetReliableMessage *crm;
1892 if (ch->pending_messages >= ch->max_pending_messages)
1894 GNUNET_break (0); /* Fails: #5370 */
1895 return GNUNET_SYSERR;
1897 if (GNUNET_YES == ch->destroy)
1899 /* we are going down, drop messages */
1902 ch->pending_messages++;
1904 if (GNUNET_YES == ch->is_loopback)
1906 struct CadetChannelClient *receiver;
1907 struct GNUNET_MQ_Envelope *env;
1908 struct GNUNET_CADET_LocalData *ld;
1911 env = GNUNET_MQ_msg_extra (ld,
1913 GNUNET_MESSAGE_TYPE_CADET_LOCAL_DATA);
1914 if ( (NULL != ch->owner) &&
1915 (sender_ccn.channel_of_client ==
1916 ch->owner->ccn.channel_of_client) )
1918 receiver = ch->dest;
1919 ack_to_owner = GNUNET_YES;
1921 else if ( (NULL != ch->dest) &&
1922 (sender_ccn.channel_of_client ==
1923 ch->dest->ccn.channel_of_client) )
1925 receiver = ch->owner;
1926 ack_to_owner = GNUNET_NO;
1931 return GNUNET_SYSERR;
1933 GNUNET_assert (NULL != receiver);
1934 ld->ccn = receiver->ccn;
1935 GNUNET_memcpy (&ld[1],
1938 if (GNUNET_YES == receiver->client_ready)
1940 ch->pending_messages--;
1941 GSC_send_to_client (receiver->c,
1943 send_ack_to_client (ch,
1948 struct CadetOutOfOrderMessage *oom;
1950 oom = GNUNET_new (struct CadetOutOfOrderMessage);
1952 GNUNET_CONTAINER_DLL_insert_tail (receiver->head_recv,
1953 receiver->tail_recv,
1955 receiver->num_recv++;
1960 /* Everything is correct, send the message. */
1961 crm = GNUNET_malloc (sizeof (*crm));
1963 crm->data_message = GNUNET_malloc (sizeof (struct GNUNET_CADET_ChannelAppDataMessage)
1965 crm->data_message->header.size = htons (sizeof (struct GNUNET_CADET_ChannelAppDataMessage) + buf_len);
1966 crm->data_message->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA);
1967 ch->mid_send.mid = htonl (ntohl (ch->mid_send.mid) + 1);
1968 crm->data_message->mid = ch->mid_send;
1969 crm->data_message->ctn = ch->ctn;
1970 GNUNET_memcpy (&crm->data_message[1],
1973 GNUNET_CONTAINER_DLL_insert_tail (ch->head_sent,
1976 LOG (GNUNET_ERROR_TYPE_DEBUG,
1977 "Sending message %u from local client to %s with %u bytes\n",
1978 ntohl (crm->data_message->mid.mid),
1981 if (NULL != ch->retry_data_task)
1983 GNUNET_SCHEDULER_cancel (ch->retry_data_task);
1984 ch->retry_data_task = NULL;
1986 crm->qe = GCT_send (ch->t,
1987 &crm->data_message->header,
1990 GNUNET_assert (NULL == ch->retry_data_task);
1996 * Handle ACK from client on local channel. Means the client is ready
1997 * for more data, see if we have any for it.
1999 * @param ch channel to destroy
2000 * @param client_ccn ccn of the client sending the ack
2003 GCCH_handle_local_ack (struct CadetChannel *ch,
2004 struct GNUNET_CADET_ClientChannelNumber client_ccn)
2006 struct CadetChannelClient *ccc;
2007 struct CadetOutOfOrderMessage *com;
2009 if ( (NULL != ch->owner) &&
2010 (ch->owner->ccn.channel_of_client == client_ccn.channel_of_client) )
2012 else if ( (NULL != ch->dest) &&
2013 (ch->dest->ccn.channel_of_client == client_ccn.channel_of_client) )
2017 ccc->client_ready = GNUNET_YES;
2018 com = ccc->head_recv;
2021 LOG (GNUNET_ERROR_TYPE_DEBUG,
2022 "Got LOCAL_ACK, %s-%X ready to receive more data, but none pending on %s-%X(%p)!\n",
2024 ntohl (client_ccn.channel_of_client),
2026 ntohl (ccc->ccn.channel_of_client),
2028 return; /* none pending */
2030 if (GNUNET_YES == ch->is_loopback)
2034 /* Messages are always in-order, just send */
2035 GNUNET_CONTAINER_DLL_remove (ccc->head_recv,
2039 GSC_send_to_client (ccc->c,
2041 /* Notify sender that we can receive more */
2042 if ( (NULL != ch->owner) &&
2043 (ccc->ccn.channel_of_client ==
2044 ch->owner->ccn.channel_of_client) )
2046 to_owner = GNUNET_NO;
2050 GNUNET_assert ( (NULL != ch->dest) &&
2051 (ccc->ccn.channel_of_client ==
2052 ch->dest->ccn.channel_of_client) );
2053 to_owner = GNUNET_YES;
2055 send_ack_to_client (ch,
2061 if ( (com->mid.mid != ch->mid_recv.mid) &&
2062 (GNUNET_NO == ch->out_of_order) &&
2063 (GNUNET_YES == ch->reliable) )
2065 LOG (GNUNET_ERROR_TYPE_DEBUG,
2066 "Got LOCAL_ACK, %s-%X ready to receive more data (but next one is out-of-order %u vs. %u)!\n",
2068 ntohl (ccc->ccn.channel_of_client),
2069 ntohl (com->mid.mid),
2070 ntohl (ch->mid_recv.mid));
2071 return; /* missing next one in-order */
2074 LOG (GNUNET_ERROR_TYPE_DEBUG,
2075 "Got LOCAL_ACK, giving payload message %u to %s-%X on %s\n",
2076 ntohl (com->mid.mid),
2078 ntohl (ccc->ccn.channel_of_client),
2081 /* all good, pass next message to client */
2082 GNUNET_CONTAINER_DLL_remove (ccc->head_recv,
2086 /* FIXME: if unreliable, this is not aggressive
2087 enough, as it would be OK to have lost some! */
2089 ch->mid_recv.mid = htonl (1 + ntohl (com->mid.mid));
2090 ch->mid_futures >>= 1; /* equivalent to division by 2 */
2091 ccc->client_ready = GNUNET_NO;
2092 GSC_send_to_client (ccc->c,
2095 send_channel_data_ack (ch);
2096 if (NULL != ccc->head_recv)
2098 if (GNUNET_NO == ch->destroy)
2100 GCT_send_channel_destroy (ch->t,
2102 channel_destroy (ch);
2106 #define LOG2(level, ...) GNUNET_log_from_nocheck(level,"cadet-chn",__VA_ARGS__)
2112 * @param ch Channel.
2113 * @param level Debug level to use.
2116 GCCH_debug (struct CadetChannel *ch,
2117 enum GNUNET_ErrorType level)
2119 #if !defined(GNUNET_CULL_LOGGING)
2122 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
2124 __FILE__, __FUNCTION__, __LINE__);
2130 LOG2 (level, "CHN *** DEBUG NULL CHANNEL ***\n");
2138 if (NULL != ch->owner)
2141 "CHN origin %s ready %s local-id: %u\n",
2142 GSC_2s (ch->owner->c),
2143 ch->owner->client_ready ? "YES" : "NO",
2144 ntohl (ch->owner->ccn.channel_of_client));
2146 if (NULL != ch->dest)
2149 "CHN destination %s ready %s local-id: %u\n",
2150 GSC_2s (ch->dest->c),
2151 ch->dest->client_ready ? "YES" : "NO",
2152 ntohl (ch->dest->ccn.channel_of_client));
2155 "CHN Message IDs recv: %d (%LLX), send: %d\n",
2156 ntohl (ch->mid_recv.mid),
2157 (unsigned long long) ch->mid_futures,
2158 ntohl (ch->mid_send.mid));
2164 /* end of gnunet-service-cadet-new_channel.c */