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.
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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 #include "gnunet_constants.h"
29 #include "gnunet_core_service.h"
34 * Context for the core service connection.
36 struct GNUNET_CORE_Handle
42 struct GNUNET_SCHEDULER_Handle *sched;
45 * Configuration we're using.
47 const struct GNUNET_CONFIGURATION_Handle *cfg;
50 * Closure for the various callbacks.
55 * Function to call once we've handshaked with the core service.
57 GNUNET_CORE_StartupCallback init;
60 * Function to call whenever we're notified about a peer connecting.
62 GNUNET_CORE_ConnectEventHandler connects;
65 * Function to call whenever we're notified about a peer disconnecting.
67 GNUNET_CORE_DisconnectEventHandler disconnects;
70 * Function to call whenever we're notified about a peer changing status.
72 GNUNET_CORE_PeerStatusEventHandler status_events;
75 * Function to call whenever we receive an inbound message.
77 GNUNET_CORE_MessageCallback inbound_notify;
80 * Function to call whenever we receive an outbound message.
82 GNUNET_CORE_MessageCallback outbound_notify;
85 * Function handlers for messages of particular type.
87 const struct GNUNET_CORE_MessageHandler *handlers;
90 * Our connection to the service for notifications.
92 struct GNUNET_CLIENT_Connection *client_notifications;
95 * Handle for our current transmission request.
97 struct GNUNET_CLIENT_TransmitHandle *cth;
100 * Head of doubly-linked list of pending requests.
102 struct GNUNET_CORE_TransmitHandle *pending_head;
105 * Tail of doubly-linked list of pending requests.
107 struct GNUNET_CORE_TransmitHandle *pending_tail;
110 * Currently submitted request (or NULL)
112 struct GNUNET_CORE_TransmitHandle *submitted;
115 * Currently submitted request based on solicitation (or NULL)
117 struct GNUNET_CORE_TransmitHandle *solicit_transmit_req;
120 * Buffer where we store a message for transmission in response
121 * to a traffic solicitation (or NULL).
123 char *solicit_buffer;
126 * How long to wait until we time out the connection attempt?
128 struct GNUNET_TIME_Absolute startup_timeout;
131 * ID of reconnect task (if any).
133 GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
136 * Number of entries in the handlers array.
141 * For inbound notifications without a specific handler, do
142 * we expect to only receive headers?
144 int inbound_hdr_only;
147 * For outbound notifications without a specific handler, do
148 * we expect to only receive headers?
150 int outbound_hdr_only;
153 * Are we currently disconnected and hence unable to forward
161 * Handle for a transmission request.
163 struct GNUNET_CORE_TransmitHandle
167 * We keep active transmit handles in a doubly-linked list.
169 struct GNUNET_CORE_TransmitHandle *next;
172 * We keep active transmit handles in a doubly-linked list.
174 struct GNUNET_CORE_TransmitHandle *prev;
177 * Corresponding core handle.
179 struct GNUNET_CORE_Handle *ch;
182 * Function that will be called to get the actual request
183 * (once we are ready to transmit this request to the core).
184 * The function will be called with a NULL buffer to signal
187 GNUNET_CONNECTION_TransmitReadyNotify get_message;
190 * Closure for get_message.
192 void *get_message_cls;
195 * If this entry is for a transmission request, pointer
196 * to the notify callback; otherwise NULL.
198 GNUNET_CONNECTION_TransmitReadyNotify notify;
201 * Closure for notify.
206 * Peer the request is about.
208 struct GNUNET_PeerIdentity peer;
211 * Timeout for this handle.
213 struct GNUNET_TIME_Absolute timeout;
216 * ID of timeout task.
218 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
221 * How important is this message?
226 * Size of this request.
235 reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
239 * Function called when we are ready to transmit our
240 * "START" message (or when this operation timed out).
243 * @param size number of bytes available in buf
244 * @param buf where the callee should write the message
245 * @return number of bytes written to buf
247 static size_t transmit_start (void *cls, size_t size, void *buf);
251 * Our current client connection went down. Clean it up
252 * and try to reconnect!
254 * @param h our handle to the core service
257 reconnect (struct GNUNET_CORE_Handle *h)
260 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
261 "Reconnecting to CORE service\n");
263 if (h->client_notifications != NULL)
264 GNUNET_CLIENT_disconnect (h->client_notifications, GNUNET_NO);
265 h->currently_down = GNUNET_YES;
266 h->client_notifications = GNUNET_CLIENT_connect (h->sched, "core", h->cfg);
267 if (h->client_notifications == NULL)
268 h->reconnect_task = GNUNET_SCHEDULER_add_delayed (h->sched,
269 GNUNET_TIME_UNIT_SECONDS,
273 h->cth = GNUNET_CLIENT_notify_transmit_ready (h->client_notifications,
274 sizeof (struct InitMessage) +
275 sizeof (uint16_t) * h->hcnt,
276 GNUNET_TIME_UNIT_SECONDS,
283 * The given request hit its timeout. Remove from the
284 * doubly-linked list and call the respective continuation.
286 * @param cls the transmit handle of the request that timed out
287 * @param tc context, can be NULL (!)
290 timeout_request (void *cls,
291 const struct GNUNET_SCHEDULER_TaskContext *tc)
293 struct GNUNET_CORE_TransmitHandle *th = cls;
295 th->timeout_task = GNUNET_SCHEDULER_NO_TASK;
297 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
298 "Signalling timeout of request for transmission to CORE service\n");
300 GNUNET_assert (0 == th->get_message (th->get_message_cls, 0, NULL));
305 * Function called when we are ready to transmit a request from our
306 * request list (or when this operation timed out).
309 * @param size number of bytes available in buf
310 * @param buf where the callee should write the message
311 * @return number of bytes written to buf
314 request_start (void *cls, size_t size, void *buf)
316 struct GNUNET_CORE_Handle *h = cls;
317 struct GNUNET_CORE_TransmitHandle *th;
321 th = h->pending_head;
324 timeout_request (th, NULL);
327 GNUNET_CONTAINER_DLL_remove (h->pending_head,
330 GNUNET_assert (h->submitted == NULL);
332 GNUNET_assert (size >= th->msize);
333 ret = th->get_message (th->get_message_cls, size, buf);
334 GNUNET_assert (ret <= size);
336 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
337 "Transmitting %u bytes to core\n",
345 * Check the list of pending requests, send the next
349 trigger_next_request (struct GNUNET_CORE_Handle *h)
351 struct GNUNET_CORE_TransmitHandle *th;
353 if (h->currently_down)
356 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
357 "In trigger_next_request, connection currently down...\n");
359 return; /* connection temporarily down */
361 if (NULL == (th = h->pending_head))
362 return; /* no requests pending */
363 GNUNET_assert (NULL == h->cth);
364 h->cth = GNUNET_CLIENT_notify_transmit_ready (h->client_notifications,
366 GNUNET_TIME_absolute_get_remaining
375 * Handler for notification messages received from the core.
377 * @param cls our "struct GNUNET_CORE_Handle"
378 * @param msg the message received from the core service
381 main_notify_handler (void *cls, const struct GNUNET_MessageHeader *msg)
383 struct GNUNET_CORE_Handle *h = cls;
385 const struct ConnectNotifyMessage *cnm;
386 const struct DisconnectNotifyMessage *dnm;
387 const struct NotifyTrafficMessage *ntm;
388 const struct GNUNET_MessageHeader *em;
389 const struct PeerStatusNotifyMessage *psnm;
392 const struct GNUNET_CORE_MessageHandler *mh;
396 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
398 ("Client was disconnected from core service, trying to reconnect.\n"));
402 msize = ntohs (msg->size);
404 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
405 "Processing message of type %u and size %u from core service\n",
406 ntohs (msg->type), msize);
408 switch (ntohs (msg->type))
410 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_CONNECT:
411 if (NULL == h->connects)
416 if (msize != sizeof (struct ConnectNotifyMessage))
421 cnm = (const struct ConnectNotifyMessage *) msg;
424 GNUNET_TIME_relative_ntoh (cnm->latency),
425 ntohl (cnm->distance));
427 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_DISCONNECT:
428 if (NULL == h->disconnects)
433 if (msize != sizeof (struct DisconnectNotifyMessage))
438 dnm = (const struct DisconnectNotifyMessage *) msg;
439 h->disconnects (h->cls,
442 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_STATUS_CHANGE:
443 if (NULL == h->status_events)
448 if (msize != sizeof (struct PeerStatusNotifyMessage))
453 psnm = (const struct PeerStatusNotifyMessage *) msg;
454 h->status_events (h->cls,
456 GNUNET_TIME_relative_ntoh (psnm->latency),
457 ntohl (psnm->distance),
460 GNUNET_TIME_absolute_ntoh (psnm->timeout));
462 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_INBOUND:
464 sizeof (struct NotifyTrafficMessage) +
465 sizeof (struct GNUNET_MessageHeader))
470 ntm = (const struct NotifyTrafficMessage *) msg;
471 em = (const struct GNUNET_MessageHeader *) &ntm[1];
473 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
474 "Received message of type %u and size %u from peer `%4s'\n",
477 GNUNET_i2s (&ntm->peer));
479 if ((GNUNET_NO == h->inbound_hdr_only) &&
480 (msize != ntohs (em->size) + sizeof (struct NotifyTrafficMessage)))
485 et = ntohs (em->type);
486 for (hpos = 0; hpos < h->hcnt; hpos++)
488 mh = &h->handlers[hpos];
491 if ((mh->expected_size != ntohs (em->size)) &&
492 (mh->expected_size != 0))
498 h->handlers[hpos].callback (h->cls, &ntm->peer, em,
499 GNUNET_TIME_relative_ntoh (ntm->latency),
500 ntohl (ntm->distance)))
502 /* error in processing, disconnect ! */
507 if (NULL != h->inbound_notify)
508 h->inbound_notify (h->cls, &ntm->peer, em,
509 GNUNET_TIME_relative_ntoh (ntm->latency),
510 ntohl (ntm->distance));
512 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_OUTBOUND:
514 sizeof (struct NotifyTrafficMessage) +
515 sizeof (struct GNUNET_MessageHeader))
520 ntm = (const struct NotifyTrafficMessage *) msg;
521 em = (const struct GNUNET_MessageHeader *) &ntm[1];
522 if ((GNUNET_NO == h->outbound_hdr_only) &&
523 (msize != ntohs (em->size) + sizeof (struct NotifyTrafficMessage)))
528 if (NULL == h->outbound_notify)
533 h->outbound_notify (h->cls, &ntm->peer, em,
534 GNUNET_TIME_relative_ntoh (ntm->latency),
535 ntohl (ntm->distance));
541 GNUNET_CLIENT_receive (h->client_notifications,
542 &main_notify_handler, h, GNUNET_TIME_UNIT_FOREVER_REL);
547 * Function called when we are ready to transmit our
548 * "START" message (or when this operation timed out).
551 * @param size number of bytes available in buf
552 * @param buf where the callee should write the message
553 * @return number of bytes written to buf
555 static size_t transmit_start (void *cls, size_t size, void *buf);
559 * Function called on the first message received from
560 * the service (contains our public key, etc.).
561 * Should trigger calling the init callback
562 * and then start our regular message processing.
565 * @param msg message received, NULL on timeout or fatal error
568 init_reply_handler (void *cls, const struct GNUNET_MessageHeader *msg)
570 struct GNUNET_CORE_Handle *h = cls;
571 const struct InitReplyMessage *m;
572 GNUNET_CORE_StartupCallback init;
573 struct GNUNET_PeerIdentity my_identity;
576 (ntohs (msg->size) != sizeof (struct InitReplyMessage)) ||
577 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_CORE_INIT_REPLY))
581 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
583 ("Error connecting to core service (failed to receive `%s' message, got message of type %u and size %u).\n"),
592 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
593 _("Failed to connect to core service, will retry.\n"));
596 transmit_start (h, 0, NULL);
599 m = (const struct InitReplyMessage *) msg;
600 /* start our message processing loop */
602 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
603 "Successfully connected to core service, starting processing loop.\n");
605 h->currently_down = GNUNET_NO;
606 trigger_next_request (h);
607 GNUNET_CLIENT_receive (h->client_notifications,
608 &main_notify_handler, h, GNUNET_TIME_UNIT_FOREVER_REL);
609 if (NULL != (init = h->init))
611 /* mark so we don't call init on reconnect */
613 GNUNET_CRYPTO_hash (&m->publicKey,
615 GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
616 &my_identity.hashPubKey);
617 init (h->cls, h, &my_identity, &m->publicKey);
623 reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
625 struct GNUNET_CORE_Handle *h = cls;
626 h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
632 * Function called when we are ready to transmit our
633 * "START" message (or when this operation timed out).
636 * @param size number of bytes available in buf
637 * @param buf where the callee should write the message
638 * @return number of bytes written to buf
641 transmit_start (void *cls, size_t size, void *buf)
643 struct GNUNET_CORE_Handle *h = cls;
644 struct InitMessage *init;
649 struct GNUNET_TIME_Relative delay;
654 if ((h->init == NULL) ||
655 (GNUNET_TIME_absolute_get ().value < h->startup_timeout.value))
657 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
658 _("Failed to connect to core service, retrying.\n"));
659 delay = GNUNET_TIME_absolute_get_remaining (h->startup_timeout);
660 if ((h->init == NULL) || (delay.value > 1000))
661 delay = GNUNET_TIME_UNIT_SECONDS;
664 GNUNET_TIME_relative_to_absolute (GNUNET_TIME_UNIT_MINUTES);
666 GNUNET_SCHEDULER_add_delayed (h->sched,
667 delay, &reconnect_task, h);
670 /* timeout on initial connect */
671 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
672 _("Failed to connect to core service, giving up.\n"));
673 h->init (h->cls, NULL, NULL, NULL);
674 GNUNET_CORE_disconnect (h);
677 msize = h->hcnt * sizeof (uint16_t) + sizeof (struct InitMessage);
678 GNUNET_assert (size >= msize);
680 init->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_INIT);
681 init->header.size = htons (msize);
682 opt = GNUNET_CORE_OPTION_NOTHING;
683 if (h->connects != NULL)
684 opt |= GNUNET_CORE_OPTION_SEND_CONNECT;
685 if (h->disconnects != NULL)
686 opt |= GNUNET_CORE_OPTION_SEND_DISCONNECT;
687 if (h->status_events != NULL)
688 opt |= GNUNET_CORE_OPTION_SEND_STATUS_CHANGE;
689 if (h->inbound_notify != NULL)
691 if (h->inbound_hdr_only)
692 opt |= GNUNET_CORE_OPTION_SEND_HDR_INBOUND;
694 opt |= GNUNET_CORE_OPTION_SEND_FULL_INBOUND;
696 if (h->outbound_notify != NULL)
698 if (h->outbound_hdr_only)
699 opt |= GNUNET_CORE_OPTION_SEND_HDR_OUTBOUND;
701 opt |= GNUNET_CORE_OPTION_SEND_FULL_OUTBOUND;
703 init->options = htonl (opt);
704 ts = (uint16_t *) & init[1];
705 for (hpos = 0; hpos < h->hcnt; hpos++)
706 ts[hpos] = htons (h->handlers[hpos].type);
707 GNUNET_CLIENT_receive (h->client_notifications,
710 GNUNET_TIME_absolute_get_remaining
711 (h->startup_timeout));
712 return sizeof (struct InitMessage) + h->hcnt * sizeof (uint16_t);
717 * Connect to the core service. Note that the connection may
718 * complete (or fail) asynchronously.
720 * @param sched scheduler to use
721 * @param cfg configuration to use
722 * @param timeout after how long should we give up trying to connect to the core service?
723 * @param cls closure for the various callbacks that follow (including handlers in the handlers array)
724 * @param init callback to call on timeout or once we have successfully
725 * connected to the core service; note that timeout is only meaningful if init is not NULL
726 * @param connects function to call on peer connect, can be NULL
727 * @param disconnects function to call on peer disconnect / timeout, can be NULL
728 * @param inbound_notify function to call for all inbound messages, can be NULL
729 * @param inbound_hdr_only set to GNUNET_YES if inbound_notify will only read the
730 * GNUNET_MessageHeader and hence we do not need to give it the full message;
731 * can be used to improve efficiency, ignored if inbound_notify is NULLL
732 * @param outbound_notify function to call for all outbound messages, can be NULL
733 * @param outbound_hdr_only set to GNUNET_YES if outbound_notify will only read the
734 * GNUNET_MessageHeader and hence we do not need to give it the full message
735 * can be used to improve efficiency, ignored if outbound_notify is NULLL
736 * @param handlers callbacks for messages we care about, NULL-terminated
737 * @return handle to the core service (only useful for disconnect until 'init' is called);
738 * NULL on error (in this case, init is never called)
740 struct GNUNET_CORE_Handle *
741 GNUNET_CORE_connect (struct GNUNET_SCHEDULER_Handle *sched,
742 const struct GNUNET_CONFIGURATION_Handle *cfg,
743 struct GNUNET_TIME_Relative timeout,
745 GNUNET_CORE_StartupCallback init,
746 GNUNET_CORE_ConnectEventHandler connects,
747 GNUNET_CORE_DisconnectEventHandler disconnects,
748 GNUNET_CORE_PeerStatusEventHandler status_events,
749 GNUNET_CORE_MessageCallback inbound_notify,
750 int inbound_hdr_only,
751 GNUNET_CORE_MessageCallback outbound_notify,
752 int outbound_hdr_only,
753 const struct GNUNET_CORE_MessageHandler *handlers)
755 struct GNUNET_CORE_Handle *h;
757 h = GNUNET_malloc (sizeof (struct GNUNET_CORE_Handle));
762 h->connects = connects;
763 h->disconnects = disconnects;
764 h->status_events = status_events;
765 h->inbound_notify = inbound_notify;
766 h->outbound_notify = outbound_notify;
767 h->inbound_hdr_only = inbound_hdr_only;
768 h->outbound_hdr_only = outbound_hdr_only;
769 h->handlers = handlers;
770 h->client_notifications = GNUNET_CLIENT_connect (sched, "core", cfg);
771 if (h->client_notifications == NULL)
776 h->startup_timeout = GNUNET_TIME_relative_to_absolute (timeout);
778 while (handlers[h->hcnt].callback != NULL)
780 GNUNET_assert (h->hcnt <
781 (GNUNET_SERVER_MAX_MESSAGE_SIZE -
782 sizeof (struct InitMessage)) / sizeof (uint16_t));
784 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
785 "Trying to connect to core service in next %llu ms.\n",
789 GNUNET_CLIENT_notify_transmit_ready (h->client_notifications,
790 sizeof (struct InitMessage) +
791 sizeof (uint16_t) * h->hcnt, timeout,
799 * Disconnect from the core service.
801 * @param handle connection to core to disconnect
804 GNUNET_CORE_disconnect (struct GNUNET_CORE_Handle *handle)
806 if (handle->cth != NULL)
807 GNUNET_CLIENT_notify_transmit_ready_cancel (handle->cth);
808 if (handle->solicit_transmit_req != NULL)
809 GNUNET_CORE_notify_transmit_ready_cancel (handle->solicit_transmit_req);
810 if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
811 GNUNET_SCHEDULER_cancel (handle->sched, handle->reconnect_task);
812 if (handle->client_notifications != NULL)
813 GNUNET_CLIENT_disconnect (handle->client_notifications, GNUNET_NO);
814 GNUNET_free_non_null (handle->solicit_buffer);
815 GNUNET_free (handle);
820 * Build the message requesting data transmission.
823 produce_send (void *cls, size_t size, void *buf)
825 struct GNUNET_CORE_TransmitHandle *th = cls;
826 struct GNUNET_CORE_Handle *h;
827 struct SendMessage *sm;
829 GNUNET_CONNECTION_TransmitReadyNotify notify;
835 /* timeout or error */
837 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
838 "P2P transmission request for `%4s' timed out.\n",
839 GNUNET_i2s(&th->peer));
841 GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
842 GNUNET_CORE_notify_transmit_ready_cancel (th);
843 trigger_next_request (h);
846 sm = (struct SendMessage *) buf;
847 sm->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_SEND);
848 sm->priority = htonl (th->priority);
849 sm->deadline = GNUNET_TIME_absolute_hton (th->timeout);
852 notify_cls = th->notify_cls;
853 GNUNET_CORE_notify_transmit_ready_cancel (th);
854 trigger_next_request (h);
855 size = GNUNET_MIN (size,
856 GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE);
857 GNUNET_assert (size >= sizeof (struct SendMessage));
858 dt = notify (notify_cls, size - sizeof (struct SendMessage), &sm[1]);
862 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
863 "Size of clients message to peer %s is 0!\n",
864 GNUNET_i2s(&th->peer));
866 /* client decided to send nothing! */
870 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
871 "Produced SEND message to core with %u bytes payload\n",
874 GNUNET_assert (dt >= sizeof (struct GNUNET_MessageHeader));
875 if (dt + sizeof (struct SendMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
881 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
882 "Preparing for P2P transmission of %u bytes to `%4s'.\n",
884 GNUNET_i2s(&th->peer));
886 sm->header.size = htons (dt + sizeof (struct SendMessage));
887 GNUNET_assert (dt + sizeof (struct SendMessage) <= size);
888 return dt + sizeof (struct SendMessage);
893 * Ask the core to call "notify" once it is ready to transmit the
894 * given number of bytes to the specified "target". If we are not yet
895 * connected to the specified peer, a call to this function will cause
896 * us to try to establish a connection.
898 * @param handle connection to core service
899 * @param priority how important is the message?
900 * @param maxdelay how long can the message wait?
901 * @param target who should receive the message,
902 * use NULL for this peer (loopback)
903 * @param notify_size how many bytes of buffer space does notify want?
904 * @param notify function to call when buffer space is available
905 * @param notify_cls closure for notify
906 * @return non-NULL if the notify callback was queued,
907 * NULL if we can not even queue the request (insufficient
908 * memory); if NULL is returned, "notify" will NOT be called.
910 struct GNUNET_CORE_TransmitHandle *
911 GNUNET_CORE_notify_transmit_ready (struct GNUNET_CORE_Handle *handle,
912 unsigned int priority,
913 struct GNUNET_TIME_Relative maxdelay,
914 const struct GNUNET_PeerIdentity *target,
916 GNUNET_CONNECTION_TransmitReadyNotify notify,
919 struct GNUNET_CORE_TransmitHandle *th;
921 GNUNET_assert (notify_size + sizeof (struct SendMessage) <
922 GNUNET_SERVER_MAX_MESSAGE_SIZE);
923 th = GNUNET_malloc (sizeof (struct GNUNET_CORE_TransmitHandle));
925 GNUNET_CONTAINER_DLL_insert_after (handle->pending_head,
926 handle->pending_tail,
927 handle->pending_tail,
929 th->get_message = &produce_send;
930 th->get_message_cls = th;
932 th->notify_cls = notify_cls;
934 th->timeout = GNUNET_TIME_relative_to_absolute (maxdelay);
935 th->timeout_task = GNUNET_SCHEDULER_add_delayed (handle->sched,
937 &timeout_request, th);
938 th->priority = priority;
939 th->msize = sizeof (struct SendMessage) + notify_size;
940 /* was the request queue previously empty? */
941 if ( (handle->pending_head == th) &&
942 (handle->cth == NULL) )
943 trigger_next_request (handle);
949 * Cancel the specified transmission-ready notification.
951 * @param th handle that was returned by "notify_transmit_ready".
954 GNUNET_CORE_notify_transmit_ready_cancel (struct GNUNET_CORE_TransmitHandle
957 struct GNUNET_CORE_Handle *h = th->ch;
959 if (h->submitted == th)
962 GNUNET_CONTAINER_DLL_remove (h->pending_head,
965 if (th->timeout_task != GNUNET_SCHEDULER_NO_TASK)
966 GNUNET_SCHEDULER_cancel (h->sched, th->timeout_task);
971 /* end of core_api.c */