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
41 * Configuration we're using.
43 const struct GNUNET_CONFIGURATION_Handle *cfg;
46 * Closure for the various callbacks.
51 * Function to call once we've handshaked with the core service.
53 GNUNET_CORE_StartupCallback init;
56 * Function to call whenever we're notified about a peer connecting.
58 GNUNET_CORE_ConnectEventHandler connects;
61 * Function to call whenever we're notified about a peer disconnecting.
63 GNUNET_CORE_DisconnectEventHandler disconnects;
66 * Function to call whenever we're notified about a peer changing status.
68 GNUNET_CORE_PeerStatusEventHandler status_events;
71 * Function to call whenever we receive an inbound message.
73 GNUNET_CORE_MessageCallback inbound_notify;
76 * Function to call whenever we receive an outbound message.
78 GNUNET_CORE_MessageCallback outbound_notify;
81 * Function handlers for messages of particular type.
83 const struct GNUNET_CORE_MessageHandler *handlers;
86 * Our connection to the service for notifications.
88 struct GNUNET_CLIENT_Connection *client_notifications;
91 * Handle for our current transmission request.
93 struct GNUNET_CLIENT_TransmitHandle *cth;
96 * Head of doubly-linked list of pending requests.
98 struct GNUNET_CORE_TransmitHandle *pending_head;
101 * Tail of doubly-linked list of pending requests.
103 struct GNUNET_CORE_TransmitHandle *pending_tail;
106 * Currently submitted request (or NULL)
108 struct GNUNET_CORE_TransmitHandle *submitted;
111 * Currently submitted request based on solicitation (or NULL)
113 struct GNUNET_CORE_TransmitHandle *solicit_transmit_req;
116 * Buffer where we store a message for transmission in response
117 * to a traffic solicitation (or NULL).
119 char *solicit_buffer;
122 * How long to wait until we time out the connection attempt?
124 struct GNUNET_TIME_Absolute startup_timeout;
127 * ID of reconnect task (if any).
129 GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
132 * Number of entries in the handlers array.
137 * For inbound notifications without a specific handler, do
138 * we expect to only receive headers?
140 int inbound_hdr_only;
143 * For outbound notifications without a specific handler, do
144 * we expect to only receive headers?
146 int outbound_hdr_only;
149 * Are we currently disconnected and hence unable to forward
157 * Handle for a transmission request.
159 struct GNUNET_CORE_TransmitHandle
163 * We keep active transmit handles in a doubly-linked list.
165 struct GNUNET_CORE_TransmitHandle *next;
168 * We keep active transmit handles in a doubly-linked list.
170 struct GNUNET_CORE_TransmitHandle *prev;
173 * Corresponding core handle.
175 struct GNUNET_CORE_Handle *ch;
178 * Function that will be called to get the actual request
179 * (once we are ready to transmit this request to the core).
180 * The function will be called with a NULL buffer to signal
183 GNUNET_CONNECTION_TransmitReadyNotify get_message;
186 * Closure for get_message.
188 void *get_message_cls;
191 * If this entry is for a transmission request, pointer
192 * to the notify callback; otherwise NULL.
194 GNUNET_CONNECTION_TransmitReadyNotify notify;
197 * Closure for notify.
202 * Peer the request is about.
204 struct GNUNET_PeerIdentity peer;
207 * Timeout for this handle.
209 struct GNUNET_TIME_Absolute timeout;
212 * ID of timeout task.
214 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
217 * How important is this message?
222 * Size of this request.
231 reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
235 * Function called when we are ready to transmit our
236 * "START" message (or when this operation timed out).
239 * @param size number of bytes available in buf
240 * @param buf where the callee should write the message
241 * @return number of bytes written to buf
243 static size_t transmit_start (void *cls, size_t size, void *buf);
247 * Our current client connection went down. Clean it up
248 * and try to reconnect!
250 * @param h our handle to the core service
253 reconnect (struct GNUNET_CORE_Handle *h)
256 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
257 "Reconnecting to CORE service\n");
259 if (h->client_notifications != NULL)
260 GNUNET_CLIENT_disconnect (h->client_notifications, GNUNET_NO);
261 h->currently_down = GNUNET_YES;
262 h->client_notifications = GNUNET_CLIENT_connect ("core", h->cfg);
263 if (h->client_notifications == NULL)
264 h->reconnect_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
268 h->cth = GNUNET_CLIENT_notify_transmit_ready (h->client_notifications,
269 sizeof (struct InitMessage) +
270 sizeof (uint16_t) * h->hcnt,
271 GNUNET_TIME_UNIT_SECONDS,
278 * The given request hit its timeout. Remove from the
279 * doubly-linked list and call the respective continuation.
281 * @param cls the transmit handle of the request that timed out
282 * @param tc context, can be NULL (!)
285 timeout_request (void *cls,
286 const struct GNUNET_SCHEDULER_TaskContext *tc)
288 struct GNUNET_CORE_TransmitHandle *th = cls;
290 th->timeout_task = GNUNET_SCHEDULER_NO_TASK;
291 GNUNET_CONTAINER_DLL_remove (th->ch->pending_head,
292 th->ch->pending_tail,
295 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
296 "Signalling timeout of request for transmission to CORE service\n");
298 GNUNET_assert (0 == th->get_message (th->get_message_cls, 0, NULL));
303 * Function called when we are ready to transmit a request from our
304 * request list (or when this operation timed out).
307 * @param size number of bytes available in buf
308 * @param buf where the callee should write the message
309 * @return number of bytes written to buf
312 request_start (void *cls, size_t size, void *buf)
314 struct GNUNET_CORE_Handle *h = cls;
315 struct GNUNET_CORE_TransmitHandle *th;
319 th = h->pending_head;
324 if (th->timeout_task != GNUNET_SCHEDULER_NO_TASK)
326 GNUNET_SCHEDULER_cancel(th->timeout_task);
327 th->timeout_task = GNUNET_SCHEDULER_NO_TASK;
329 timeout_request (th, NULL);
332 GNUNET_CONTAINER_DLL_remove (h->pending_head,
335 GNUNET_assert (h->submitted == NULL);
337 GNUNET_assert (size >= th->msize);
338 ret = th->get_message (th->get_message_cls, size, buf);
339 GNUNET_assert (ret <= size);
341 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
342 "Transmitting %u bytes to core\n",
350 * Check the list of pending requests, send the next
354 trigger_next_request (struct GNUNET_CORE_Handle *h)
356 struct GNUNET_CORE_TransmitHandle *th;
358 if (h->currently_down)
361 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
362 "In trigger_next_request, connection currently down...\n");
364 return; /* connection temporarily down */
366 if (NULL == (th = h->pending_head))
367 return; /* no requests pending */
368 GNUNET_assert (NULL == h->cth);
369 h->cth = GNUNET_CLIENT_notify_transmit_ready (h->client_notifications,
371 GNUNET_TIME_absolute_get_remaining
380 * Handler for notification messages received from the core.
382 * @param cls our "struct GNUNET_CORE_Handle"
383 * @param msg the message received from the core service
386 main_notify_handler (void *cls, const struct GNUNET_MessageHeader *msg)
388 struct GNUNET_CORE_Handle *h = cls;
390 const struct ConnectNotifyMessage *cnm;
391 const struct DisconnectNotifyMessage *dnm;
392 const struct NotifyTrafficMessage *ntm;
393 const struct GNUNET_MessageHeader *em;
394 const struct PeerStatusNotifyMessage *psnm;
397 const struct GNUNET_CORE_MessageHandler *mh;
401 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
403 ("Client was disconnected from core service, trying to reconnect.\n"));
407 msize = ntohs (msg->size);
409 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
410 "Processing message of type %u and size %u from core service\n",
411 ntohs (msg->type), msize);
413 switch (ntohs (msg->type))
415 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_CONNECT:
416 if (NULL == h->connects)
421 if (msize != sizeof (struct ConnectNotifyMessage))
426 cnm = (const struct ConnectNotifyMessage *) msg;
429 GNUNET_TIME_relative_ntoh (cnm->latency),
430 ntohl (cnm->distance));
432 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_DISCONNECT:
433 if (NULL == h->disconnects)
438 if (msize != sizeof (struct DisconnectNotifyMessage))
443 dnm = (const struct DisconnectNotifyMessage *) msg;
444 h->disconnects (h->cls,
447 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_STATUS_CHANGE:
448 if (NULL == h->status_events)
453 if (msize != sizeof (struct PeerStatusNotifyMessage))
458 psnm = (const struct PeerStatusNotifyMessage *) msg;
459 h->status_events (h->cls,
461 GNUNET_TIME_relative_ntoh (psnm->latency),
462 ntohl (psnm->distance),
465 GNUNET_TIME_absolute_ntoh (psnm->timeout));
467 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_INBOUND:
469 sizeof (struct NotifyTrafficMessage) +
470 sizeof (struct GNUNET_MessageHeader))
475 ntm = (const struct NotifyTrafficMessage *) msg;
476 em = (const struct GNUNET_MessageHeader *) &ntm[1];
478 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
479 "Received message of type %u and size %u from peer `%4s'\n",
482 GNUNET_i2s (&ntm->peer));
484 if ((GNUNET_NO == h->inbound_hdr_only) &&
485 (msize != ntohs (em->size) + sizeof (struct NotifyTrafficMessage)))
490 et = ntohs (em->type);
491 for (hpos = 0; hpos < h->hcnt; hpos++)
493 mh = &h->handlers[hpos];
496 if ((mh->expected_size != ntohs (em->size)) &&
497 (mh->expected_size != 0))
503 h->handlers[hpos].callback (h->cls, &ntm->peer, em,
504 GNUNET_TIME_relative_ntoh (ntm->latency),
505 ntohl (ntm->distance)))
507 /* error in processing, do not process other messages! */
511 if (NULL != h->inbound_notify)
512 h->inbound_notify (h->cls, &ntm->peer, em,
513 GNUNET_TIME_relative_ntoh (ntm->latency),
514 ntohl (ntm->distance));
516 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_OUTBOUND:
518 sizeof (struct NotifyTrafficMessage) +
519 sizeof (struct GNUNET_MessageHeader))
524 ntm = (const struct NotifyTrafficMessage *) msg;
525 em = (const struct GNUNET_MessageHeader *) &ntm[1];
526 if ((GNUNET_NO == h->outbound_hdr_only) &&
527 (msize != ntohs (em->size) + sizeof (struct NotifyTrafficMessage)))
532 if (NULL == h->outbound_notify)
537 h->outbound_notify (h->cls, &ntm->peer, em,
538 GNUNET_TIME_relative_ntoh (ntm->latency),
539 ntohl (ntm->distance));
545 GNUNET_CLIENT_receive (h->client_notifications,
546 &main_notify_handler, h, GNUNET_TIME_UNIT_FOREVER_REL);
551 * Function called when we are ready to transmit our
552 * "START" message (or when this operation timed out).
555 * @param size number of bytes available in buf
556 * @param buf where the callee should write the message
557 * @return number of bytes written to buf
559 static size_t transmit_start (void *cls, size_t size, void *buf);
563 * Function called on the first message received from
564 * the service (contains our public key, etc.).
565 * Should trigger calling the init callback
566 * and then start our regular message processing.
569 * @param msg message received, NULL on timeout or fatal error
572 init_reply_handler (void *cls, const struct GNUNET_MessageHeader *msg)
574 struct GNUNET_CORE_Handle *h = cls;
575 const struct InitReplyMessage *m;
576 GNUNET_CORE_StartupCallback init;
577 struct GNUNET_PeerIdentity my_identity;
580 (ntohs (msg->size) != sizeof (struct InitReplyMessage)) ||
581 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_CORE_INIT_REPLY))
585 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
587 ("Error connecting to core service (failed to receive `%s' message, got message of type %u and size %u).\n"),
596 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
597 _("Failed to connect to core service, will retry.\n"));
600 transmit_start (h, 0, NULL);
603 m = (const struct InitReplyMessage *) msg;
604 GNUNET_break (0 == ntohl (m->reserved));
605 /* start our message processing loop */
607 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
608 "Successfully connected to core service, starting processing loop.\n");
610 h->currently_down = GNUNET_NO;
611 trigger_next_request (h);
612 GNUNET_CLIENT_receive (h->client_notifications,
613 &main_notify_handler, h, GNUNET_TIME_UNIT_FOREVER_REL);
614 if (NULL != (init = h->init))
616 /* mark so we don't call init on reconnect */
618 GNUNET_CRYPTO_hash (&m->publicKey,
620 GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
621 &my_identity.hashPubKey);
622 init (h->cls, h, &my_identity, &m->publicKey);
628 reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
630 struct GNUNET_CORE_Handle *h = cls;
631 h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
637 * Function called when we are ready to transmit our
638 * "START" message (or when this operation timed out).
641 * @param size number of bytes available in buf
642 * @param buf where the callee should write the message
643 * @return number of bytes written to buf
646 transmit_start (void *cls, size_t size, void *buf)
648 struct GNUNET_CORE_Handle *h = cls;
649 struct InitMessage *init;
654 struct GNUNET_TIME_Relative delay;
659 if ((h->init == NULL) ||
660 (GNUNET_TIME_absolute_get ().abs_value < h->startup_timeout.abs_value))
662 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
663 _("Failed to connect to core service, retrying.\n"));
664 delay = GNUNET_TIME_absolute_get_remaining (h->startup_timeout);
665 if ((h->init == NULL) || (delay.rel_value > 1000))
666 delay = GNUNET_TIME_UNIT_SECONDS;
669 GNUNET_TIME_relative_to_absolute (GNUNET_TIME_UNIT_MINUTES);
671 GNUNET_SCHEDULER_add_delayed (delay, &reconnect_task, h);
674 /* timeout on initial connect */
675 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
676 _("Failed to connect to core service, giving up.\n"));
677 h->init (h->cls, NULL, NULL, NULL);
678 GNUNET_CORE_disconnect (h);
681 msize = h->hcnt * sizeof (uint16_t) + sizeof (struct InitMessage);
682 GNUNET_assert (size >= msize);
684 init->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_INIT);
685 init->header.size = htons (msize);
686 opt = GNUNET_CORE_OPTION_NOTHING;
687 if (h->connects != NULL)
688 opt |= GNUNET_CORE_OPTION_SEND_CONNECT;
689 if (h->disconnects != NULL)
690 opt |= GNUNET_CORE_OPTION_SEND_DISCONNECT;
691 if (h->status_events != NULL)
692 opt |= GNUNET_CORE_OPTION_SEND_STATUS_CHANGE;
693 if (h->inbound_notify != NULL)
695 if (h->inbound_hdr_only)
696 opt |= GNUNET_CORE_OPTION_SEND_HDR_INBOUND;
698 opt |= GNUNET_CORE_OPTION_SEND_FULL_INBOUND;
700 if (h->outbound_notify != NULL)
702 if (h->outbound_hdr_only)
703 opt |= GNUNET_CORE_OPTION_SEND_HDR_OUTBOUND;
705 opt |= GNUNET_CORE_OPTION_SEND_FULL_OUTBOUND;
707 init->options = htonl (opt);
708 ts = (uint16_t *) & init[1];
709 for (hpos = 0; hpos < h->hcnt; hpos++)
710 ts[hpos] = htons (h->handlers[hpos].type);
711 GNUNET_CLIENT_receive (h->client_notifications,
714 GNUNET_TIME_absolute_get_remaining
715 (h->startup_timeout));
716 return sizeof (struct InitMessage) + h->hcnt * sizeof (uint16_t);
721 * Connect to the core service. Note that the connection may
722 * complete (or fail) asynchronously.
724 * @param cfg configuration to use
725 * @param timeout after how long should we give up trying to connect to the core service?
726 * @param cls closure for the various callbacks that follow (including handlers in the handlers array)
727 * @param init callback to call on timeout or once we have successfully
728 * connected to the core service; note that timeout is only meaningful if init is not NULL
729 * @param connects function to call on peer connect, can be NULL
730 * @param disconnects function to call on peer disconnect / timeout, can be NULL
731 * @param status_events function to call on changes to peer connection status, can be NULL
732 * @param inbound_notify function to call for all inbound messages, can be NULL
733 * @param inbound_hdr_only set to GNUNET_YES if inbound_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 inbound_notify is NULLL
736 * @param outbound_notify function to call for all outbound messages, can be NULL
737 * @param outbound_hdr_only set to GNUNET_YES if outbound_notify will only read the
738 * GNUNET_MessageHeader and hence we do not need to give it the full message
739 * can be used to improve efficiency, ignored if outbound_notify is NULLL
740 * @param handlers callbacks for messages we care about, NULL-terminated
741 * @return handle to the core service (only useful for disconnect until 'init' is called);
742 * NULL on error (in this case, init is never called)
744 struct GNUNET_CORE_Handle *
745 GNUNET_CORE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
746 struct GNUNET_TIME_Relative timeout,
748 GNUNET_CORE_StartupCallback init,
749 GNUNET_CORE_ConnectEventHandler connects,
750 GNUNET_CORE_DisconnectEventHandler disconnects,
751 GNUNET_CORE_PeerStatusEventHandler status_events,
752 GNUNET_CORE_MessageCallback inbound_notify,
753 int inbound_hdr_only,
754 GNUNET_CORE_MessageCallback outbound_notify,
755 int outbound_hdr_only,
756 const struct GNUNET_CORE_MessageHandler *handlers)
758 struct GNUNET_CORE_Handle *h;
760 h = GNUNET_malloc (sizeof (struct GNUNET_CORE_Handle));
764 h->connects = connects;
765 h->disconnects = disconnects;
766 h->status_events = status_events;
767 h->inbound_notify = inbound_notify;
768 h->outbound_notify = outbound_notify;
769 h->inbound_hdr_only = inbound_hdr_only;
770 h->outbound_hdr_only = outbound_hdr_only;
771 h->handlers = handlers;
772 h->client_notifications = GNUNET_CLIENT_connect ("core", cfg);
773 if (h->client_notifications == NULL)
778 h->startup_timeout = GNUNET_TIME_relative_to_absolute (timeout);
780 while (handlers[h->hcnt].callback != NULL)
782 GNUNET_assert (h->hcnt <
783 (GNUNET_SERVER_MAX_MESSAGE_SIZE -
784 sizeof (struct InitMessage)) / sizeof (uint16_t));
786 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
787 "Trying to connect to core service in next %llu ms.\n",
791 GNUNET_CLIENT_notify_transmit_ready (h->client_notifications,
792 sizeof (struct InitMessage) +
793 sizeof (uint16_t) * h->hcnt, timeout,
801 * Disconnect from the core service.
803 * @param handle connection to core to disconnect
806 GNUNET_CORE_disconnect (struct GNUNET_CORE_Handle *handle)
808 if (handle->cth != NULL)
809 GNUNET_CLIENT_notify_transmit_ready_cancel (handle->cth);
810 if (handle->solicit_transmit_req != NULL)
811 GNUNET_CORE_notify_transmit_ready_cancel (handle->solicit_transmit_req);
812 if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
813 GNUNET_SCHEDULER_cancel (handle->reconnect_task);
814 if (handle->client_notifications != NULL)
815 GNUNET_CLIENT_disconnect (handle->client_notifications, GNUNET_NO);
816 GNUNET_break (handle->pending_head == NULL);
817 GNUNET_free_non_null (handle->solicit_buffer);
818 GNUNET_free (handle);
823 * Build the message requesting data transmission.
826 produce_send (void *cls, size_t size, void *buf)
828 struct GNUNET_CORE_TransmitHandle *th = cls;
829 struct GNUNET_CORE_Handle *h;
830 struct SendMessage *sm;
832 GNUNET_CONNECTION_TransmitReadyNotify notify;
838 /* timeout or error */
840 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
841 "P2P transmission request for `%4s' timed out.\n",
842 GNUNET_i2s(&th->peer));
844 GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
845 GNUNET_CORE_notify_transmit_ready_cancel (th);
846 if ((h->pending_head == th) && (h->cth != NULL)) /* Request hasn't been canceled yet! */
848 GNUNET_CLIENT_notify_transmit_ready_cancel (h->cth);
850 trigger_next_request (h);
852 /* Otherwise this request timed out, but another is actually queued for sending, so don't try to send another! */
855 sm = (struct SendMessage *) buf;
856 sm->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_SEND);
857 sm->priority = htonl (th->priority);
858 sm->deadline = GNUNET_TIME_absolute_hton (th->timeout);
861 notify_cls = th->notify_cls;
862 GNUNET_CORE_notify_transmit_ready_cancel (th);
863 trigger_next_request (h);
864 size = GNUNET_MIN (size,
865 GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE);
866 GNUNET_assert (size >= sizeof (struct SendMessage));
867 dt = notify (notify_cls, size - sizeof (struct SendMessage), &sm[1]);
871 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
872 "Size of clients message to peer %s is 0!\n",
873 GNUNET_i2s(&sm->peer));
875 /* client decided to send nothing! */
879 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
880 "Produced SEND message to core with %u bytes payload\n",
883 GNUNET_assert (dt >= sizeof (struct GNUNET_MessageHeader));
884 if (dt + sizeof (struct SendMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
890 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
891 "Preparing for P2P transmission of %u bytes to `%4s'.\n",
893 GNUNET_i2s(&sm->peer));
895 sm->header.size = htons (dt + sizeof (struct SendMessage));
896 GNUNET_assert (dt + sizeof (struct SendMessage) <= size);
897 return dt + sizeof (struct SendMessage);
902 * Ask the core to call "notify" once it is ready to transmit the
903 * given number of bytes to the specified "target". If we are not yet
904 * connected to the specified peer, a call to this function will cause
905 * us to try to establish a connection.
907 * @param handle connection to core service
908 * @param priority how important is the message?
909 * @param maxdelay how long can the message wait?
910 * @param target who should receive the message,
911 * use NULL for this peer (loopback)
912 * @param notify_size how many bytes of buffer space does notify want?
913 * @param notify function to call when buffer space is available
914 * @param notify_cls closure for notify
915 * @return non-NULL if the notify callback was queued,
916 * NULL if we can not even queue the request (insufficient
917 * memory); if NULL is returned, "notify" will NOT be called.
919 struct GNUNET_CORE_TransmitHandle *
920 GNUNET_CORE_notify_transmit_ready (struct GNUNET_CORE_Handle *handle,
921 unsigned int priority,
922 struct GNUNET_TIME_Relative maxdelay,
923 const struct GNUNET_PeerIdentity *target,
925 GNUNET_CONNECTION_TransmitReadyNotify notify,
928 struct GNUNET_CORE_TransmitHandle *th;
930 GNUNET_assert (notify_size + sizeof (struct SendMessage) <
931 GNUNET_SERVER_MAX_MESSAGE_SIZE);
932 th = GNUNET_malloc (sizeof (struct GNUNET_CORE_TransmitHandle));
934 GNUNET_CONTAINER_DLL_insert_after (handle->pending_head,
935 handle->pending_tail,
936 handle->pending_tail,
938 th->get_message = &produce_send;
939 th->get_message_cls = th;
941 th->notify_cls = notify_cls;
943 th->timeout = GNUNET_TIME_relative_to_absolute (maxdelay);
944 th->timeout_task = GNUNET_SCHEDULER_add_delayed (maxdelay,
945 &timeout_request, th);
946 th->priority = priority;
947 th->msize = sizeof (struct SendMessage) + notify_size;
948 /* was the request queue previously empty? */
949 if ( (handle->pending_head == th) &&
950 (handle->cth == NULL) )
951 trigger_next_request (handle);
957 * Cancel the specified transmission-ready notification.
959 * @param th handle that was returned by "notify_transmit_ready".
962 GNUNET_CORE_notify_transmit_ready_cancel (struct GNUNET_CORE_TransmitHandle
965 struct GNUNET_CORE_Handle *h = th->ch;
967 if (h->submitted == th)
970 GNUNET_CONTAINER_DLL_remove (h->pending_head,
973 if (th->timeout_task != GNUNET_SCHEDULER_NO_TASK)
974 GNUNET_SCHEDULER_cancel (th->timeout_task);
979 /* end of core_api.c */