2 This file is part of GNUnet.
3 (C) 2009, 2010 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.
22 * @file core/core_api.c
23 * @brief core service; this is the main API for encrypted P2P
25 * @author Christian Grothoff
28 * - implement atsi parsing and passing
31 #include "gnunet_constants.h"
32 #include "gnunet_core_service.h"
37 * Information we track for each peer.
43 * We generally do NOT keep peer records in a DLL; this
44 * DLL is only used IF this peer's 'pending_head' message
45 * is ready for transmission.
47 struct PeerRecord *prev;
50 * We generally do NOT keep peer records in a DLL; this
51 * DLL is only used IF this peer's 'pending_head' message
52 * is ready for transmission.
54 struct PeerRecord *next;
57 * Peer the record is about.
59 struct GNUNET_PeerIdentity peer;
62 * Corresponding core handle.
64 struct GNUNET_CORE_Handle *ch;
67 * Head of doubly-linked list of pending requests.
68 * Requests are sorted by deadline *except* for HEAD,
69 * which is only modified upon transmission to core.
71 struct GNUNET_CORE_TransmitHandle *pending_head;
74 * Tail of doubly-linked list of pending requests.
76 struct GNUNET_CORE_TransmitHandle *pending_tail;
79 * Pending callback waiting for peer information, or NULL for none.
81 GNUNET_CORE_PeerConfigurationInfoCallback pcic;
89 * Request information ID for the given pcic (needed in case a
90 * request is cancelled after being submitted to core and a new
91 * one is generated; in this case, we need to avoid matching the
92 * reply to the first (cancelled) request to the second request).
97 * ID of timeout task for the 'pending_head' handle
98 * which is the one with the smallest timeout.
100 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
103 * Current size of the queue of pending requests.
105 unsigned int queue_size;
108 * SendMessageRequest ID generator for this peer.
116 * Entry in a doubly-linked list of control messages to be transmitted
117 * to the core service. Control messages include traffic allocation,
118 * connection requests and of course our initial 'init' request.
120 * The actual message is allocated at the end of this struct.
122 struct ControlMessage
125 * This is a doubly-linked list.
127 struct ControlMessage *next;
130 * This is a doubly-linked list.
132 struct ControlMessage *prev;
135 * Function to run after successful transmission (or call with
136 * reason 'TIMEOUT' on error); called with scheduler context 'NULL'
139 GNUNET_SCHEDULER_Task cont;
142 * Closure for 'cont'.
147 * Transmit handle (if one is associated with this ControlMessage), or NULL.
149 struct GNUNET_CORE_TransmitHandle *th;
155 * Context for the core service connection.
157 struct GNUNET_CORE_Handle
161 * Configuration we're using.
163 const struct GNUNET_CONFIGURATION_Handle *cfg;
166 * Closure for the various callbacks.
171 * Function to call once we've handshaked with the core service.
173 GNUNET_CORE_StartupCallback init;
176 * Function to call whenever we're notified about a peer connecting.
178 GNUNET_CORE_ConnectEventHandler connects;
181 * Function to call whenever we're notified about a peer disconnecting.
183 GNUNET_CORE_DisconnectEventHandler disconnects;
186 * Function to call whenever we're notified about a peer changing status.
188 GNUNET_CORE_PeerStatusEventHandler status_events;
191 * Function to call whenever we receive an inbound message.
193 GNUNET_CORE_MessageCallback inbound_notify;
196 * Function to call whenever we receive an outbound message.
198 GNUNET_CORE_MessageCallback outbound_notify;
201 * Function handlers for messages of particular type.
203 const struct GNUNET_CORE_MessageHandler *handlers;
206 * Our connection to the service.
208 struct GNUNET_CLIENT_Connection *client;
211 * Handle for our current transmission request.
213 struct GNUNET_CLIENT_TransmitHandle *cth;
216 * Head of doubly-linked list of pending requests.
218 struct ControlMessage *pending_head;
221 * Tail of doubly-linked list of pending requests.
223 struct ControlMessage *pending_tail;
226 * Head of doubly-linked list of peers that are core-approved
227 * to send their next message.
229 struct PeerRecord *ready_peer_head;
232 * Tail of doubly-linked list of peers that are core-approved
233 * to send their next message.
235 struct PeerRecord *ready_peer_tail;
238 * Hash map listing all of the peers that we are currently
241 struct GNUNET_CONTAINER_MultiHashMap *peers;
244 * Identity of this peer.
246 struct GNUNET_PeerIdentity me;
249 * ID of reconnect task (if any).
251 GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
254 * Current delay we use for re-trying to connect to core.
256 struct GNUNET_TIME_Relative retry_backoff;
259 * Request information ID generator.
264 * Number of messages we are allowed to queue per target.
266 unsigned int queue_size;
269 * Number of entries in the handlers array.
274 * For inbound notifications without a specific handler, do
275 * we expect to only receive headers?
277 int inbound_hdr_only;
280 * For outbound notifications without a specific handler, do
281 * we expect to only receive headers?
283 int outbound_hdr_only;
286 * Are we currently disconnected and hence unable to forward
295 * Handle for a transmission request.
297 struct GNUNET_CORE_TransmitHandle
301 * We keep active transmit handles in a doubly-linked list.
303 struct GNUNET_CORE_TransmitHandle *next;
306 * We keep active transmit handles in a doubly-linked list.
308 struct GNUNET_CORE_TransmitHandle *prev;
311 * Corresponding peer record.
313 struct PeerRecord *peer;
316 * Corresponding SEND_REQUEST message. Only non-NULL
317 * while SEND_REQUEST message is pending.
319 struct ControlMessage *cm;
322 * Function that will be called to get the actual request
323 * (once we are ready to transmit this request to the core).
324 * The function will be called with a NULL buffer to signal
327 GNUNET_CONNECTION_TransmitReadyNotify get_message;
330 * Closure for get_message.
332 void *get_message_cls;
335 * Timeout for this handle.
337 struct GNUNET_TIME_Absolute timeout;
340 * How important is this message?
345 * Size of this request.
350 * Send message request ID for this request.
358 * Our current client connection went down. Clean it up
359 * and try to reconnect!
361 * @param h our handle to the core service
364 reconnect (struct GNUNET_CORE_Handle *h);
368 * Task schedule to try to re-connect to core.
370 * @param cls the 'struct GNUNET_CORE_Handle'
371 * @param tc task context
374 reconnect_task (void *cls,
375 const struct GNUNET_SCHEDULER_TaskContext *tc)
377 struct GNUNET_CORE_Handle *h = cls;
379 h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
381 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
382 "Connecting to CORE service after delay\n");
389 * Notify clients about disconnect and free
390 * the entry for connected peer.
392 * @param cls the 'struct GNUNET_CORE_Handle*'
393 * @param key the peer identity (not used)
394 * @param value the 'struct PeerRecord' to free.
395 * @return GNUNET_YES (continue)
398 disconnect_and_free_peer_entry (void *cls,
399 const GNUNET_HashCode *key,
402 static struct GNUNET_BANDWIDTH_Value32NBO zero;
403 struct GNUNET_CORE_Handle *h = cls;
404 struct GNUNET_CORE_TransmitHandle *th;
405 struct PeerRecord *pr = value;
406 GNUNET_CORE_PeerConfigurationInfoCallback pcic;
408 while (NULL != (th = pr->pending_head))
410 GNUNET_CONTAINER_DLL_remove (pr->pending_head,
415 th->get_message (th->get_message_cls,
419 if (NULL != (pcic = pr->pcic))
427 if (pr->timeout_task != GNUNET_SCHEDULER_NO_TASK)
429 GNUNET_SCHEDULER_cancel (pr->timeout_task);
430 pr->timeout_task = GNUNET_SCHEDULER_NO_TASK;
432 GNUNET_assert (pr->queue_size == 0);
433 if ( (pr->prev != NULL) ||
434 (pr->next != NULL) ||
435 (h->ready_peer_head == pr) )
436 GNUNET_CONTAINER_DLL_remove (h->ready_peer_head,
439 if (h->disconnects != NULL)
440 h->disconnects (h->cls,
442 GNUNET_assert (GNUNET_YES ==
443 GNUNET_CONTAINER_multihashmap_remove (h->peers,
446 GNUNET_assert (pr->pending_head == NULL);
447 GNUNET_assert (pr->pending_tail == NULL);
448 GNUNET_assert (pr->ch = h);
449 GNUNET_assert (pr->queue_size == 0);
450 GNUNET_assert (pr->timeout_task == GNUNET_SCHEDULER_NO_TASK);
457 * Close down any existing connection to the CORE service and
458 * try re-establishing it later.
460 * @param h our handle
463 reconnect_later (struct GNUNET_CORE_Handle *h)
465 struct ControlMessage *cm;
467 while (NULL != (cm = h->pending_head))
469 GNUNET_CONTAINER_DLL_remove (h->pending_head,
474 if (cm->cont != NULL)
475 cm->cont (cm->cont_cls, NULL);
478 if (h->client != NULL)
480 GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
482 GNUNET_CONTAINER_multihashmap_iterate (h->peers,
483 &disconnect_and_free_peer_entry,
486 GNUNET_assert (h->pending_head == NULL);
487 h->currently_down = GNUNET_YES;
488 GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_TASK);
489 h->retry_backoff = GNUNET_TIME_relative_min (GNUNET_TIME_UNIT_SECONDS,
491 h->reconnect_task = GNUNET_SCHEDULER_add_delayed (h->retry_backoff,
494 h->retry_backoff = GNUNET_TIME_relative_multiply (h->retry_backoff, 2);
499 * Check the list of pending requests, send the next
502 * @param h core handle
503 * @param ignore_currently_down transmit message even if not initialized?
506 trigger_next_request (struct GNUNET_CORE_Handle *h,
507 int ignore_currently_down);
511 * The given request hit its timeout. Remove from the
512 * doubly-linked list and call the respective continuation.
514 * @param cls the transmit handle of the request that timed out
515 * @param tc context, can be NULL (!)
518 transmission_timeout (void *cls,
519 const struct GNUNET_SCHEDULER_TaskContext *tc);
523 * Send a control message to the peer asking for transmission
524 * of the message in the given peer record.
526 * @param pr peer to request transmission to
529 request_next_transmission (struct PeerRecord *pr)
531 struct GNUNET_CORE_Handle *h = pr->ch;
532 struct ControlMessage *cm;
533 struct SendMessageRequest *smr;
534 struct GNUNET_CORE_TransmitHandle *th;
536 if (pr->timeout_task != GNUNET_SCHEDULER_NO_TASK)
538 GNUNET_SCHEDULER_cancel (pr->timeout_task);
539 pr->timeout_task = GNUNET_SCHEDULER_NO_TASK;
541 if (NULL == (th = pr->pending_head))
543 trigger_next_request (h, GNUNET_NO);
546 GNUNET_assert (pr->prev == NULL);
547 GNUNET_assert (pr->next == NULL);
548 pr->timeout_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining (th->timeout),
549 &transmission_timeout,
551 cm = GNUNET_malloc (sizeof (struct ControlMessage) +
552 sizeof (struct SendMessageRequest));
555 smr = (struct SendMessageRequest*) &cm[1];
556 smr->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_SEND_REQUEST);
557 smr->header.size = htons (sizeof (struct SendMessageRequest));
558 smr->priority = htonl (th->priority);
559 smr->deadline = GNUNET_TIME_absolute_hton (th->timeout);
560 smr->peer = pr->peer;
561 smr->queue_size = htonl (pr->queue_size);
562 smr->size = htons (th->msize);
563 smr->smr_id = htons (th->smr_id = pr->smr_id_gen++);
564 GNUNET_CONTAINER_DLL_insert_after (h->pending_head,
569 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
570 "Adding SEND REQUEST for peer `%s' to message queue\n",
571 GNUNET_i2s (&pr->peer));
573 trigger_next_request (h, GNUNET_NO);
578 * The given request hit its timeout. Remove from the
579 * doubly-linked list and call the respective continuation.
581 * @param cls the transmit handle of the request that timed out
582 * @param tc context, can be NULL (!)
585 transmission_timeout (void *cls,
586 const struct GNUNET_SCHEDULER_TaskContext *tc)
588 struct PeerRecord *pr = cls;
589 struct GNUNET_CORE_TransmitHandle *th;
591 pr->timeout_task = GNUNET_SCHEDULER_NO_TASK;
592 th = pr->pending_head;
593 GNUNET_CONTAINER_DLL_remove (pr->pending_head,
598 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
599 "Signalling timeout of request for transmission to CORE service\n");
601 GNUNET_assert (0 == th->get_message (th->get_message_cls, 0, NULL));
602 request_next_transmission (pr);
607 * Transmit the next message to the core service.
610 transmit_message (void *cls,
614 struct GNUNET_CORE_Handle *h = cls;
615 struct ControlMessage *cm;
616 struct GNUNET_CORE_TransmitHandle *th;
617 struct PeerRecord *pr;
618 struct SendMessage *sm;
619 const struct GNUNET_MessageHeader *hdr;
627 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
628 "Transmission failed, initiating reconnect\n");
633 /* first check for control messages */
634 if (NULL != (cm = h->pending_head))
636 hdr = (const struct GNUNET_MessageHeader*) &cm[1];
637 msize = ntohs (hdr->size);
640 trigger_next_request (h, GNUNET_NO);
644 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
645 "Transmitting control message with %u bytes of type %u to core.\n",
646 (unsigned int) msize,
647 (unsigned int) ntohs (hdr->type));
649 memcpy (buf, hdr, msize);
650 GNUNET_CONTAINER_DLL_remove (h->pending_head,
655 if (NULL != cm->cont)
656 GNUNET_SCHEDULER_add_continuation (cm->cont,
658 GNUNET_SCHEDULER_REASON_PREREQ_DONE);
660 trigger_next_request (h, GNUNET_NO);
663 /* now check for 'ready' P2P messages */
664 if (NULL != (pr = h->ready_peer_head))
666 th = pr->pending_head;
667 if (size < th->msize + sizeof (struct SendMessage))
669 trigger_next_request (h, GNUNET_NO);
672 GNUNET_CONTAINER_DLL_remove (h->ready_peer_head,
675 GNUNET_CONTAINER_DLL_remove (pr->pending_head,
679 if (pr->timeout_task != GNUNET_SCHEDULER_NO_TASK)
681 GNUNET_SCHEDULER_cancel (pr->timeout_task);
682 pr->timeout_task = GNUNET_SCHEDULER_NO_TASK;
685 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
686 "Transmitting SEND request to `%s' with %u bytes.\n",
687 GNUNET_i2s (&pr->peer),
688 (unsigned int) th->msize);
690 sm = (struct SendMessage *) buf;
691 sm->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_SEND);
692 sm->priority = htonl (th->priority);
693 sm->deadline = GNUNET_TIME_absolute_hton (th->timeout);
695 ret = th->get_message (th->get_message_cls,
696 size - sizeof (struct SendMessage),
702 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
703 "Size of clients message to peer %s is 0!\n",
704 GNUNET_i2s(&pr->peer));
706 /* client decided to send nothing! */
707 request_next_transmission (pr);
711 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
712 "Produced SEND message to core with %u bytes payload\n",
715 GNUNET_assert (ret >= sizeof (struct GNUNET_MessageHeader));
716 if (ret + sizeof (struct SendMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
719 request_next_transmission (pr);
722 ret += sizeof (struct SendMessage);
723 sm->header.size = htons (ret);
724 GNUNET_assert (ret <= size);
726 request_next_transmission (pr);
734 * Check the list of pending requests, send the next
737 * @param h core handle
738 * @param ignore_currently_down transmit message even if not initialized?
741 trigger_next_request (struct GNUNET_CORE_Handle *h,
742 int ignore_currently_down)
746 if ( (GNUNET_YES == h->currently_down) &&
747 (ignore_currently_down == GNUNET_NO) )
750 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
751 "Core connection down, not processing queue\n");
758 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
759 "Request pending, not processing queue\n");
763 if (h->pending_head != NULL)
764 msize = ntohs (((struct GNUNET_MessageHeader*) &h->pending_head[1])->size);
765 else if (h->ready_peer_head != NULL)
766 msize = h->ready_peer_head->pending_head->msize + sizeof (struct SendMessage);
770 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
771 "Request queue empty, not processing queue\n");
773 return; /* no pending message */
775 h->cth = GNUNET_CLIENT_notify_transmit_ready (h->client,
777 GNUNET_TIME_UNIT_FOREVER_REL,
779 &transmit_message, h);
784 * Handler for notification messages received from the core.
786 * @param cls our "struct GNUNET_CORE_Handle"
787 * @param msg the message received from the core service
790 main_notify_handler (void *cls,
791 const struct GNUNET_MessageHeader *msg)
793 struct GNUNET_CORE_Handle *h = cls;
794 const struct InitReplyMessage *m;
795 const struct ConnectNotifyMessage *cnm;
796 const struct DisconnectNotifyMessage *dnm;
797 const struct NotifyTrafficMessage *ntm;
798 const struct GNUNET_MessageHeader *em;
799 const struct ConfigurationInfoMessage *cim;
800 const struct PeerStatusNotifyMessage *psnm;
801 const struct SendMessageReady *smr;
802 const struct GNUNET_CORE_MessageHandler *mh;
803 GNUNET_CORE_StartupCallback init;
804 GNUNET_CORE_PeerConfigurationInfoCallback pcic;
805 struct PeerRecord *pr;
806 struct GNUNET_CORE_TransmitHandle *th;
814 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
816 ("Client was disconnected from core service, trying to reconnect.\n"));
820 msize = ntohs (msg->size);
822 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
823 "Processing message of type %u and size %u from core service\n",
824 ntohs (msg->type), msize);
826 switch (ntohs (msg->type))
828 case GNUNET_MESSAGE_TYPE_CORE_INIT_REPLY:
829 if (ntohs (msg->size) != sizeof (struct InitReplyMessage))
835 m = (const struct InitReplyMessage *) msg;
836 GNUNET_break (0 == ntohl (m->reserved));
837 /* start our message processing loop */
838 if (GNUNET_YES == h->currently_down)
840 h->currently_down = GNUNET_NO;
841 trigger_next_request (h, GNUNET_NO);
843 h->retry_backoff = GNUNET_TIME_UNIT_MILLISECONDS;
844 if (NULL != (init = h->init))
846 /* mark so we don't call init on reconnect */
848 GNUNET_CRYPTO_hash (&m->publicKey,
850 GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
853 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
854 "Connected to core service of peer `%s'.\n",
855 GNUNET_i2s (&h->me));
857 init (h->cls, h, &h->me, &m->publicKey);
862 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
863 "Successfully reconnected to core service.\n");
867 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_CONNECT:
868 if (msize != sizeof (struct ConnectNotifyMessage))
874 cnm = (const struct ConnectNotifyMessage *) msg;
876 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
877 "Received notification about connection from `%s'.\n",
878 GNUNET_i2s (&cnm->peer));
880 if (0 == memcmp (&h->me,
882 sizeof (struct GNUNET_PeerIdentity)))
884 /* disconnect from self!? */
888 pr = GNUNET_CONTAINER_multihashmap_get (h->peers,
889 &cnm->peer.hashPubKey);
896 pr = GNUNET_malloc (sizeof (struct PeerRecord));
897 pr->peer = cnm->peer;
899 GNUNET_assert (GNUNET_YES ==
900 GNUNET_CONTAINER_multihashmap_put (h->peers,
901 &cnm->peer.hashPubKey,
903 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST));
904 if (NULL != h->connects)
907 NULL /* FIXME: atsi! */);
909 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_DISCONNECT:
910 if (msize != sizeof (struct DisconnectNotifyMessage))
916 dnm = (const struct DisconnectNotifyMessage *) msg;
917 if (0 == memcmp (&h->me,
919 sizeof (struct GNUNET_PeerIdentity)))
921 /* connection to self!? */
926 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
927 "Received notification about disconnect from `%s'.\n",
928 GNUNET_i2s (&dnm->peer));
930 pr = GNUNET_CONTAINER_multihashmap_get (h->peers,
931 &dnm->peer.hashPubKey);
938 trigger = ( (pr->prev != NULL) ||
939 (pr->next != NULL) ||
940 (h->ready_peer_head == pr) );
941 disconnect_and_free_peer_entry (h, &dnm->peer.hashPubKey, pr);
943 trigger_next_request (h, GNUNET_NO);
945 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_STATUS_CHANGE:
946 if (NULL == h->status_events)
951 if (msize != sizeof (struct PeerStatusNotifyMessage))
957 psnm = (const struct PeerStatusNotifyMessage *) msg;
958 if (0 == memcmp (&h->me,
960 sizeof (struct GNUNET_PeerIdentity)))
967 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
968 "Received notification about status change by `%s'.\n",
969 GNUNET_i2s (&psnm->peer));
971 pr = GNUNET_CONTAINER_multihashmap_get (h->peers,
972 &psnm->peer.hashPubKey);
979 h->status_events (h->cls,
983 GNUNET_TIME_absolute_ntoh (psnm->timeout),
984 NULL /* FIXME: atsi */);
986 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_INBOUND:
988 sizeof (struct NotifyTrafficMessage) +
989 sizeof (struct GNUNET_MessageHeader))
995 ntm = (const struct NotifyTrafficMessage *) msg;
996 if (0 == memcmp (&h->me,
998 sizeof (struct GNUNET_PeerIdentity)))
1004 em = (const struct GNUNET_MessageHeader *) &ntm[1];
1006 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1007 "Received message of type %u and size %u from peer `%4s'\n",
1010 GNUNET_i2s (&ntm->peer));
1012 pr = GNUNET_CONTAINER_multihashmap_get (h->peers,
1013 &ntm->peer.hashPubKey);
1017 reconnect_later (h);
1020 if ((GNUNET_NO == h->inbound_hdr_only) &&
1021 (msize != ntohs (em->size) + sizeof (struct NotifyTrafficMessage)))
1024 reconnect_later (h);
1027 et = ntohs (em->type);
1028 for (hpos = 0; hpos < h->hcnt; hpos++)
1030 mh = &h->handlers[hpos];
1033 if ((mh->expected_size != ntohs (em->size)) &&
1034 (mh->expected_size != 0))
1040 h->handlers[hpos].callback (h->cls, &ntm->peer, em,
1041 NULL /* FIXME: atsi */))
1043 /* error in processing, do not process other messages! */
1047 if (NULL != h->inbound_notify)
1048 h->inbound_notify (h->cls, &ntm->peer, em,
1049 NULL /* FIXME: atsi */);
1051 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_OUTBOUND:
1053 sizeof (struct NotifyTrafficMessage) +
1054 sizeof (struct GNUNET_MessageHeader))
1057 reconnect_later (h);
1060 ntm = (const struct NotifyTrafficMessage *) msg;
1061 if (0 == memcmp (&h->me,
1063 sizeof (struct GNUNET_PeerIdentity)))
1069 em = (const struct GNUNET_MessageHeader *) &ntm[1];
1070 pr = GNUNET_CONTAINER_multihashmap_get (h->peers,
1071 &ntm->peer.hashPubKey);
1075 reconnect_later (h);
1079 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1080 "Received notification about transmission to `%s'.\n",
1081 GNUNET_i2s (&ntm->peer));
1083 if ((GNUNET_NO == h->outbound_hdr_only) &&
1084 (msize != ntohs (em->size) + sizeof (struct NotifyTrafficMessage)))
1087 reconnect_later (h);
1090 if (NULL == h->outbound_notify)
1095 h->outbound_notify (h->cls, &ntm->peer, em,
1096 NULL /* FIXME: atsi? */);
1098 case GNUNET_MESSAGE_TYPE_CORE_SEND_READY:
1099 if (msize != sizeof (struct SendMessageReady))
1102 reconnect_later (h);
1105 smr = (const struct SendMessageReady *) msg;
1106 if (0 == memcmp (&h->me,
1108 sizeof (struct GNUNET_PeerIdentity)))
1114 pr = GNUNET_CONTAINER_multihashmap_get (h->peers,
1115 &smr->peer.hashPubKey);
1119 reconnect_later (h);
1123 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1124 "Received notification about transmission readiness to `%s'.\n",
1125 GNUNET_i2s (&smr->peer));
1127 th = pr->pending_head;
1128 if (ntohs (smr->smr_id) != th->smr_id)
1130 /* READY message is for expired or cancelled message,
1131 ignore! (we should have already sent another request) */
1134 if ( (pr->prev != NULL) ||
1135 (pr->next != NULL) ||
1136 (h->ready_peer_head == pr) )
1138 /* we should not already be on the ready list... */
1140 reconnect_later (h);
1143 GNUNET_CONTAINER_DLL_insert (h->ready_peer_head,
1146 trigger_next_request (h, GNUNET_NO);
1148 case GNUNET_MESSAGE_TYPE_CORE_CONFIGURATION_INFO:
1149 if (ntohs (msg->size) != sizeof (struct ConfigurationInfoMessage))
1152 reconnect_later (h);
1155 cim = (const struct ConfigurationInfoMessage*) msg;
1156 if (0 == memcmp (&h->me,
1158 sizeof (struct GNUNET_PeerIdentity)))
1165 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1166 "Received notification about configuration update for `%s'.\n",
1167 GNUNET_i2s (&cim->peer));
1169 pr = GNUNET_CONTAINER_multihashmap_get (h->peers,
1170 &cim->peer.hashPubKey);
1174 reconnect_later (h);
1177 if (pr->rim_id != ntohl (cim->rim_id))
1185 ntohl (cim->reserved_amount),
1186 GNUNET_ntohll (cim->preference));
1189 reconnect_later (h);
1192 GNUNET_CLIENT_receive (h->client,
1193 &main_notify_handler, h,
1194 GNUNET_TIME_UNIT_FOREVER_REL);
1199 * Task executed once we are done transmitting the INIT message.
1200 * Starts our 'receive' loop.
1202 * @param cls the 'struct GNUNET_CORE_Handle'
1203 * @param tc task context
1206 init_done_task (void *cls,
1207 const struct GNUNET_SCHEDULER_TaskContext *tc)
1209 struct GNUNET_CORE_Handle *h = cls;
1213 if (0 == (tc->reason & GNUNET_SCHEDULER_REASON_PREREQ_DONE))
1216 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1217 "Failed to exchange INIT with core, retrying\n");
1219 reconnect_later (h);
1222 GNUNET_CLIENT_receive (h->client,
1223 &main_notify_handler,
1225 GNUNET_TIME_UNIT_FOREVER_REL);
1230 * Our current client connection went down. Clean it up
1231 * and try to reconnect!
1233 * @param h our handle to the core service
1236 reconnect (struct GNUNET_CORE_Handle *h)
1238 struct ControlMessage *cm;
1239 struct InitMessage *init;
1246 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1247 "Reconnecting to CORE service\n");
1249 GNUNET_assert (h->client == NULL);
1250 GNUNET_assert (h->currently_down == GNUNET_YES);
1251 h->client = GNUNET_CLIENT_connect ("core", h->cfg);
1252 if (h->client == NULL)
1254 reconnect_later (h);
1257 msize = h->hcnt * sizeof (uint16_t) + sizeof (struct InitMessage);
1258 cm = GNUNET_malloc (sizeof (struct ControlMessage) +
1260 cm->cont = &init_done_task;
1262 init = (struct InitMessage*) &cm[1];
1263 init->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_INIT);
1264 init->header.size = htons (msize);
1265 opt = GNUNET_CORE_OPTION_SEND_CONNECT | GNUNET_CORE_OPTION_SEND_DISCONNECT;
1266 if (h->status_events != NULL)
1267 opt |= GNUNET_CORE_OPTION_SEND_STATUS_CHANGE;
1268 if (h->inbound_notify != NULL)
1270 if (h->inbound_hdr_only)
1271 opt |= GNUNET_CORE_OPTION_SEND_HDR_INBOUND;
1273 opt |= GNUNET_CORE_OPTION_SEND_FULL_INBOUND;
1275 if (h->outbound_notify != NULL)
1277 if (h->outbound_hdr_only)
1278 opt |= GNUNET_CORE_OPTION_SEND_HDR_OUTBOUND;
1280 opt |= GNUNET_CORE_OPTION_SEND_FULL_OUTBOUND;
1282 init->options = htonl (opt);
1283 ts = (uint16_t *) &init[1];
1284 for (hpos = 0; hpos < h->hcnt; hpos++)
1285 ts[hpos] = htons (h->handlers[hpos].type);
1286 GNUNET_CONTAINER_DLL_insert (h->pending_head,
1289 trigger_next_request (h, GNUNET_YES);
1295 * Connect to the core service. Note that the connection may
1296 * complete (or fail) asynchronously.
1298 * @param cfg configuration to use
1299 * @param queue_size size of the per-peer message queue
1300 * @param cls closure for the various callbacks that follow (including handlers in the handlers array)
1301 * @param init callback to call on timeout or once we have successfully
1302 * connected to the core service; note that timeout is only meaningful if init is not NULL
1303 * @param connects function to call on peer connect, can be NULL
1304 * @param disconnects function to call on peer disconnect / timeout, can be NULL
1305 * @param status_events function to call on changes to peer connection status, can be NULL
1306 * @param inbound_notify function to call for all inbound messages, can be NULL
1307 * @param inbound_hdr_only set to GNUNET_YES if inbound_notify will only read the
1308 * GNUNET_MessageHeader and hence we do not need to give it the full message;
1309 * can be used to improve efficiency, ignored if inbound_notify is NULLL
1310 * @param outbound_notify function to call for all outbound messages, can be NULL
1311 * @param outbound_hdr_only set to GNUNET_YES if outbound_notify will only read the
1312 * GNUNET_MessageHeader and hence we do not need to give it the full message
1313 * can be used to improve efficiency, ignored if outbound_notify is NULLL
1314 * @param handlers callbacks for messages we care about, NULL-terminated
1315 * @return handle to the core service (only useful for disconnect until 'init' is called);
1316 * NULL on error (in this case, init is never called)
1318 struct GNUNET_CORE_Handle *
1319 GNUNET_CORE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
1320 unsigned int queue_size,
1322 GNUNET_CORE_StartupCallback init,
1323 GNUNET_CORE_ConnectEventHandler connects,
1324 GNUNET_CORE_DisconnectEventHandler disconnects,
1325 GNUNET_CORE_PeerStatusEventHandler status_events,
1326 GNUNET_CORE_MessageCallback inbound_notify,
1327 int inbound_hdr_only,
1328 GNUNET_CORE_MessageCallback outbound_notify,
1329 int outbound_hdr_only,
1330 const struct GNUNET_CORE_MessageHandler *handlers)
1332 struct GNUNET_CORE_Handle *h;
1334 h = GNUNET_malloc (sizeof (struct GNUNET_CORE_Handle));
1336 h->queue_size = queue_size;
1339 h->connects = connects;
1340 h->disconnects = disconnects;
1341 h->status_events = status_events;
1342 h->inbound_notify = inbound_notify;
1343 h->outbound_notify = outbound_notify;
1344 h->inbound_hdr_only = inbound_hdr_only;
1345 h->outbound_hdr_only = outbound_hdr_only;
1346 h->handlers = handlers;
1348 h->currently_down = GNUNET_YES;
1349 h->peers = GNUNET_CONTAINER_multihashmap_create (128);
1350 h->retry_backoff = GNUNET_TIME_UNIT_MILLISECONDS;
1351 while (handlers[h->hcnt].callback != NULL)
1353 GNUNET_assert (h->hcnt <
1354 (GNUNET_SERVER_MAX_MESSAGE_SIZE -
1355 sizeof (struct InitMessage)) / sizeof (uint16_t));
1357 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1358 "Connecting to CORE service\n");
1366 * Disconnect from the core service. This function can only
1367 * be called *after* all pending 'GNUNET_CORE_notify_transmit_ready'
1368 * requests have been explicitly cancelled.
1370 * @param handle connection to core to disconnect
1373 GNUNET_CORE_disconnect (struct GNUNET_CORE_Handle *handle)
1375 struct ControlMessage *cm;
1378 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1379 "Disconnecting from CORE service\n");
1381 if (handle->cth != NULL)
1383 GNUNET_CLIENT_notify_transmit_ready_cancel (handle->cth);
1386 if (handle->client != NULL)
1388 GNUNET_CLIENT_disconnect (handle->client, GNUNET_NO);
1389 handle->client = NULL;
1391 if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
1393 GNUNET_SCHEDULER_cancel (handle->reconnect_task);
1394 handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1396 while (NULL != (cm = handle->pending_head))
1398 GNUNET_CONTAINER_DLL_remove (handle->pending_head,
1399 handle->pending_tail,
1403 if (cm->cont != NULL)
1404 cm->cont (cm->cont_cls, NULL);
1407 GNUNET_CONTAINER_multihashmap_iterate (handle->peers,
1408 &disconnect_and_free_peer_entry,
1410 GNUNET_CONTAINER_multihashmap_destroy (handle->peers);
1411 GNUNET_break (handle->ready_peer_head == NULL);
1412 GNUNET_free (handle);
1417 * Ask the core to call "notify" once it is ready to transmit the
1418 * given number of bytes to the specified "target". If we are not yet
1419 * connected to the specified peer, a call to this function will cause
1420 * us to try to establish a connection.
1422 * @param handle connection to core service
1423 * @param priority how important is the message?
1424 * @param maxdelay how long can the message wait?
1425 * @param target who should receive the message,
1426 * use NULL for this peer (loopback)
1427 * @param notify_size how many bytes of buffer space does notify want?
1428 * @param notify function to call when buffer space is available
1429 * @param notify_cls closure for notify
1430 * @return non-NULL if the notify callback was queued,
1431 * NULL if we can not even queue the request (insufficient
1432 * memory); if NULL is returned, "notify" will NOT be called.
1434 struct GNUNET_CORE_TransmitHandle *
1435 GNUNET_CORE_notify_transmit_ready (struct GNUNET_CORE_Handle *handle,
1437 struct GNUNET_TIME_Relative maxdelay,
1438 const struct GNUNET_PeerIdentity *target,
1440 GNUNET_CONNECTION_TransmitReadyNotify notify,
1443 struct PeerRecord *pr;
1444 struct GNUNET_CORE_TransmitHandle *th;
1445 struct GNUNET_CORE_TransmitHandle *pos;
1446 struct GNUNET_CORE_TransmitHandle *prev;
1447 struct GNUNET_CORE_TransmitHandle *minp;
1449 pr = GNUNET_CONTAINER_multihashmap_get (handle->peers,
1450 &target->hashPubKey);
1453 /* attempt to send to peer that is not connected */
1454 GNUNET_log(GNUNET_ERROR_TYPE_WARNING,
1455 "Attempting to send to peer `%s' from peer `%s', but not connected!\n",
1456 GNUNET_i2s(target), GNUNET_h2s(&handle->me.hashPubKey));
1460 GNUNET_assert (notify_size + sizeof (struct SendMessage) <
1461 GNUNET_SERVER_MAX_MESSAGE_SIZE);
1462 th = GNUNET_malloc (sizeof (struct GNUNET_CORE_TransmitHandle));
1464 th->get_message = notify;
1465 th->get_message_cls = notify_cls;
1466 th->timeout = GNUNET_TIME_relative_to_absolute (maxdelay);
1467 th->priority = priority;
1468 th->msize = notify_size;
1469 /* bound queue size */
1470 if (pr->queue_size == handle->queue_size)
1472 /* find lowest-priority entry */
1473 minp = pr->pending_head;
1475 while (prev != NULL)
1477 if (prev->priority < minp->priority)
1483 GNUNET_break (handle->queue_size != 0);
1484 GNUNET_break (pr->queue_size == 0);
1487 if (priority <= minp->priority)
1490 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1491 "Dropping transmission request: priority too low\n");
1493 return NULL; /* priority too low */
1495 GNUNET_CONTAINER_DLL_remove (pr->pending_head,
1500 minp->get_message (minp->get_message_cls,
1505 /* Order entries by deadline, but SKIP 'HEAD' if
1506 we're in the 'ready_peer_*' DLL */
1507 pos = pr->pending_head;
1508 if ( (pr->prev != NULL) ||
1509 (pr->next != NULL) ||
1510 (pr == handle->ready_peer_head) )
1512 GNUNET_assert (pos != NULL);
1513 pos = pos->next; /* skip head */
1516 /* insertion sort */
1518 while ( (pos != NULL) &&
1519 (pos->timeout.abs_value < th->timeout.abs_value) )
1524 GNUNET_CONTAINER_DLL_insert_after (pr->pending_head,
1529 /* was the request queue previously empty? */
1531 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1532 "Transmission request added to queue\n");
1534 if (pr->pending_head == th)
1535 request_next_transmission (pr);
1541 * Cancel the specified transmission-ready notification.
1543 * @param th handle that was returned by "notify_transmit_ready".
1546 GNUNET_CORE_notify_transmit_ready_cancel (struct GNUNET_CORE_TransmitHandle
1549 struct PeerRecord *pr = th->peer;
1550 struct GNUNET_CORE_Handle *h = pr->ch;
1553 was_head = (pr->pending_head == th);
1554 GNUNET_CONTAINER_DLL_remove (pr->pending_head,
1560 /* we're currently in the control queue, remove */
1561 GNUNET_CONTAINER_DLL_remove (h->pending_head,
1564 GNUNET_free (th->cm);
1569 if ( (pr->prev != NULL) ||
1570 (pr->next != NULL) ||
1571 (pr == h->ready_peer_head) )
1573 /* the request that was 'approved' by core was
1574 cancelled before it could be transmitted; remove
1575 us from the 'ready' list */
1576 GNUNET_CONTAINER_DLL_remove (h->ready_peer_head,
1580 request_next_transmission (pr);
1585 /* ****************** GNUNET_CORE_peer_request_connect ******************** */
1588 * Handle for a request to the core to connect to
1589 * a particular peer. Can be used to cancel the request
1590 * (before the 'cont'inuation is called).
1592 struct GNUNET_CORE_PeerRequestHandle
1596 * Link to control message.
1598 struct ControlMessage *cm;
1603 struct GNUNET_CORE_Handle *h;
1606 * Continuation to run when done.
1608 GNUNET_SCHEDULER_Task cont;
1611 * Closure for 'cont'.
1619 * Continuation called when the control message was transmitted.
1620 * Calls the original continuation and frees the remaining
1623 * @param cls the 'struct GNUNET_CORE_PeerRequestHandle'
1624 * @param tc scheduler context
1627 peer_request_connect_cont (void *cls,
1628 const struct GNUNET_SCHEDULER_TaskContext *tc)
1630 struct GNUNET_CORE_PeerRequestHandle *ret = cls;
1632 if (ret->cont != NULL)
1635 GNUNET_SCHEDULER_add_now (ret->cont,
1638 ret->cont (ret->cont_cls, tc);
1645 * Request that the core should try to connect to a particular peer.
1646 * Once the request has been transmitted to the core, the continuation
1647 * function will be called. Note that this does NOT mean that a
1648 * connection was successfully established -- it only means that the
1649 * core will now try. Successful establishment of the connection
1650 * will be signalled to the 'connects' callback argument of
1651 * 'GNUNET_CORE_connect' only. If the core service does not respond
1652 * to our connection attempt within the given time frame, 'cont' will
1653 * be called with the TIMEOUT reason code.
1655 * @param h core handle
1656 * @param timeout how long to try to talk to core
1657 * @param peer who should we connect to
1658 * @param cont function to call once the request has been completed (or timed out)
1659 * @param cont_cls closure for cont
1660 * @return NULL on error (cont will not be called), otherwise handle for cancellation
1662 struct GNUNET_CORE_PeerRequestHandle *
1663 GNUNET_CORE_peer_request_connect (struct GNUNET_CORE_Handle *h,
1664 struct GNUNET_TIME_Relative timeout,
1665 const struct GNUNET_PeerIdentity * peer,
1666 GNUNET_SCHEDULER_Task cont,
1669 struct GNUNET_CORE_PeerRequestHandle *ret;
1670 struct ControlMessage *cm;
1671 struct ConnectMessage *msg;
1673 cm = GNUNET_malloc (sizeof (struct ControlMessage) +
1674 sizeof (struct ConnectMessage));
1675 msg = (struct ConnectMessage*) &cm[1];
1676 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_REQUEST_CONNECT);
1677 msg->header.size = htons (sizeof (struct ConnectMessage));
1678 msg->reserved = htonl (0);
1679 msg->timeout = GNUNET_TIME_relative_hton (timeout);
1681 GNUNET_CONTAINER_DLL_insert (h->pending_head,
1684 ret = GNUNET_malloc (sizeof (struct GNUNET_CORE_PeerRequestHandle));
1688 ret->cont_cls = cont_cls;
1689 cm->cont = &peer_request_connect_cont;
1692 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1693 "Queueing REQUEST_CONNECT request\n");
1695 if (h->pending_head == cm)
1696 trigger_next_request (h, GNUNET_NO);
1702 * Cancel a pending request to connect to a particular peer. Must not
1703 * be called after the 'cont' function was invoked.
1705 * @param req request handle that was returned for the original request
1708 GNUNET_CORE_peer_request_connect_cancel (struct GNUNET_CORE_PeerRequestHandle *req)
1710 struct GNUNET_CORE_Handle *h = req->h;
1711 struct ControlMessage *cm = req->cm;
1713 GNUNET_CONTAINER_DLL_remove (h->pending_head,
1721 /* ****************** GNUNET_CORE_peer_change_preference ******************** */
1724 struct GNUNET_CORE_InformationRequestContext
1728 * Our connection to the service.
1730 struct GNUNET_CORE_Handle *h;
1733 * Function to call with the information.
1735 GNUNET_CORE_PeerConfigurationInfoCallback info;
1743 * Link to control message, NULL if CM was sent.
1745 struct ControlMessage *cm;
1748 * Link to peer record.
1750 struct PeerRecord *pr;
1755 * CM was sent, remove link so we don't double-free.
1757 * @param cls the 'struct GNUNET_CORE_InformationRequestContext'
1758 * @param tc scheduler context
1761 change_preference_send_continuation (void *cls,
1762 const struct GNUNET_SCHEDULER_TaskContext *tc)
1764 struct GNUNET_CORE_InformationRequestContext *irc = cls;
1771 * Obtain statistics and/or change preferences for the given peer.
1773 * @param h core handle
1774 * @param peer identifies the peer
1775 * @param timeout after how long should we give up (and call "info" with NULL
1776 * for "peer" to signal an error)?
1777 * @param bw_out set to the current bandwidth limit (sending) for this peer,
1778 * caller should set "bw_out" to "-1" to avoid changing
1779 * the current value; otherwise "bw_out" will be lowered to
1780 * the specified value; passing a pointer to "0" can be used to force
1781 * us to disconnect from the peer; "bw_out" might not increase
1782 * as specified since the upper bound is generally
1783 * determined by the other peer!
1784 * @param amount reserve N bytes for receiving, negative
1785 * amounts can be used to undo a (recent) reservation;
1786 * @param preference increase incoming traffic share preference by this amount;
1787 * in the absence of "amount" reservations, we use this
1788 * preference value to assign proportional bandwidth shares
1789 * to all connected peers
1790 * @param info function to call with the resulting configuration information
1791 * @param info_cls closure for info
1792 * @return NULL on error
1794 struct GNUNET_CORE_InformationRequestContext *
1795 GNUNET_CORE_peer_change_preference (struct GNUNET_CORE_Handle *h,
1796 const struct GNUNET_PeerIdentity *peer,
1797 struct GNUNET_TIME_Relative timeout,
1798 struct GNUNET_BANDWIDTH_Value32NBO bw_out,
1800 uint64_t preference,
1801 GNUNET_CORE_PeerConfigurationInfoCallback info,
1804 struct GNUNET_CORE_InformationRequestContext *irc;
1805 struct PeerRecord *pr;
1806 struct RequestInfoMessage *rim;
1807 struct ControlMessage *cm;
1809 pr = GNUNET_CONTAINER_multihashmap_get (h->peers,
1813 /* attempt to change preference on peer that is not connected */
1817 if (pr->pcic != NULL)
1819 /* second change before first one is done */
1823 irc = GNUNET_malloc (sizeof (struct GNUNET_CORE_InformationRequestContext));
1827 irc->info_cls = info_cls;
1828 cm = GNUNET_malloc (sizeof (struct ControlMessage) +
1829 sizeof (struct RequestInfoMessage));
1830 cm->cont = &change_preference_send_continuation;
1833 rim = (struct RequestInfoMessage*) &cm[1];
1834 rim->header.size = htons (sizeof (struct RequestInfoMessage));
1835 rim->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_REQUEST_INFO);
1836 rim->rim_id = htonl (pr->rim_id = h->rim_id_gen++);
1837 rim->limit_outbound = bw_out;
1838 rim->reserve_inbound = htonl (amount);
1839 rim->preference_change = GNUNET_htonll(preference);
1842 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1843 "Queueing CHANGE PREFERENCE request\n");
1845 GNUNET_CONTAINER_DLL_insert (h->pending_head,
1849 pr->pcic_cls = info_cls;
1850 if (h->pending_head == cm)
1851 trigger_next_request (h, GNUNET_NO);
1857 * Cancel request for getting information about a peer.
1858 * Note that an eventual change in preference, trust or bandwidth
1859 * assignment MAY have already been committed at the time,
1860 * so cancelling a request is NOT sure to undo the original
1861 * request. The original request may or may not still commit.
1862 * The only thing cancellation ensures is that the callback
1863 * from the original request will no longer be called.
1865 * @param irc context returned by the original GNUNET_CORE_peer_get_info call
1868 GNUNET_CORE_peer_change_preference_cancel (struct GNUNET_CORE_InformationRequestContext *irc)
1870 struct GNUNET_CORE_Handle *h = irc->h;
1871 struct PeerRecord *pr = irc->pr;
1873 if (irc->cm != NULL)
1875 GNUNET_CONTAINER_DLL_remove (h->pending_head,
1878 GNUNET_free (irc->cm);
1881 pr->pcic_cls = NULL;
1886 /* end of core_api.c */