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 #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 messages we should queue per target.
134 unsigned int queue_size;
137 * Number of entries in the handlers array.
142 * For inbound notifications without a specific handler, do
143 * we expect to only receive headers?
145 int inbound_hdr_only;
148 * For outbound notifications without a specific handler, do
149 * we expect to only receive headers?
151 int outbound_hdr_only;
154 * Are we currently disconnected and hence unable to forward
162 * Handle for a transmission request.
164 struct GNUNET_CORE_TransmitHandle
168 * We keep active transmit handles in a doubly-linked list.
170 struct GNUNET_CORE_TransmitHandle *next;
173 * We keep active transmit handles in a doubly-linked list.
175 struct GNUNET_CORE_TransmitHandle *prev;
178 * Corresponding core handle.
180 struct GNUNET_CORE_Handle *ch;
183 * Function that will be called to get the actual request
184 * (once we are ready to transmit this request to the core).
185 * The function will be called with a NULL buffer to signal
188 GNUNET_CONNECTION_TransmitReadyNotify get_message;
191 * Closure for get_message.
193 void *get_message_cls;
196 * If this entry is for a transmission request, pointer
197 * to the notify callback; otherwise NULL.
199 GNUNET_CONNECTION_TransmitReadyNotify notify;
202 * Closure for notify.
207 * Peer the request is about.
209 struct GNUNET_PeerIdentity peer;
212 * Timeout for this handle.
214 struct GNUNET_TIME_Absolute timeout;
217 * ID of timeout task.
219 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
222 * How important is this message?
227 * Size of this request.
236 reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
240 * Function called when we are ready to transmit our
241 * "START" message (or when this operation timed out).
244 * @param size number of bytes available in buf
245 * @param buf where the callee should write the message
246 * @return number of bytes written to buf
248 static size_t transmit_start (void *cls, size_t size, void *buf);
252 * Our current client connection went down. Clean it up
253 * and try to reconnect!
255 * @param h our handle to the core service
258 reconnect (struct GNUNET_CORE_Handle *h)
261 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
262 "Reconnecting to CORE service\n");
264 if (h->client_notifications != NULL)
265 GNUNET_CLIENT_disconnect (h->client_notifications, GNUNET_NO);
266 h->currently_down = GNUNET_YES;
267 h->client_notifications = GNUNET_CLIENT_connect ("core", h->cfg);
268 if (h->client_notifications == NULL)
269 h->reconnect_task = GNUNET_SCHEDULER_add_delayed (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;
296 GNUNET_CONTAINER_DLL_remove (th->ch->pending_head,
297 th->ch->pending_tail,
300 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
301 "Signalling timeout of request for transmission to CORE service\n");
303 GNUNET_assert (0 == th->get_message (th->get_message_cls, 0, NULL));
308 * Function called when we are ready to transmit a request from our
309 * request list (or when this operation timed out).
312 * @param size number of bytes available in buf
313 * @param buf where the callee should write the message
314 * @return number of bytes written to buf
317 request_start (void *cls, size_t size, void *buf)
319 struct GNUNET_CORE_Handle *h = cls;
320 struct GNUNET_CORE_TransmitHandle *th;
324 th = h->pending_head;
329 if (th->timeout_task != GNUNET_SCHEDULER_NO_TASK)
331 GNUNET_SCHEDULER_cancel(th->timeout_task);
332 th->timeout_task = GNUNET_SCHEDULER_NO_TASK;
334 timeout_request (th, NULL);
337 GNUNET_CONTAINER_DLL_remove (h->pending_head,
340 GNUNET_assert (h->submitted == NULL);
342 GNUNET_assert (size >= th->msize);
343 ret = th->get_message (th->get_message_cls, size, buf);
344 GNUNET_assert (ret <= size);
346 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
347 "Transmitting %u bytes to core\n",
355 * Check the list of pending requests, send the next
359 trigger_next_request (struct GNUNET_CORE_Handle *h)
361 struct GNUNET_CORE_TransmitHandle *th;
363 if (h->currently_down)
366 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
367 "In trigger_next_request, connection currently down...\n");
369 return; /* connection temporarily down */
371 if (NULL == (th = h->pending_head))
372 return; /* no requests pending */
373 GNUNET_assert (NULL == h->cth);
374 h->cth = GNUNET_CLIENT_notify_transmit_ready (h->client_notifications,
376 GNUNET_TIME_absolute_get_remaining
385 * Handler for notification messages received from the core.
387 * @param cls our "struct GNUNET_CORE_Handle"
388 * @param msg the message received from the core service
391 main_notify_handler (void *cls, const struct GNUNET_MessageHeader *msg)
393 struct GNUNET_CORE_Handle *h = cls;
395 const struct ConnectNotifyMessage *cnm;
396 const struct DisconnectNotifyMessage *dnm;
397 const struct NotifyTrafficMessage *ntm;
398 const struct GNUNET_MessageHeader *em;
399 const struct PeerStatusNotifyMessage *psnm;
402 const struct GNUNET_CORE_MessageHandler *mh;
406 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
408 ("Client was disconnected from core service, trying to reconnect.\n"));
412 msize = ntohs (msg->size);
414 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
415 "Processing message of type %u and size %u from core service\n",
416 ntohs (msg->type), msize);
418 switch (ntohs (msg->type))
420 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_CONNECT:
421 if (NULL == h->connects)
426 if (msize != sizeof (struct ConnectNotifyMessage))
431 cnm = (const struct ConnectNotifyMessage *) msg;
434 GNUNET_TIME_relative_ntoh (cnm->latency),
435 ntohl (cnm->distance));
437 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_DISCONNECT:
438 if (NULL == h->disconnects)
443 if (msize != sizeof (struct DisconnectNotifyMessage))
448 dnm = (const struct DisconnectNotifyMessage *) msg;
449 h->disconnects (h->cls,
452 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_STATUS_CHANGE:
453 if (NULL == h->status_events)
458 if (msize != sizeof (struct PeerStatusNotifyMessage))
463 psnm = (const struct PeerStatusNotifyMessage *) msg;
464 h->status_events (h->cls,
466 GNUNET_TIME_relative_ntoh (psnm->latency),
467 ntohl (psnm->distance),
470 GNUNET_TIME_absolute_ntoh (psnm->timeout));
472 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_INBOUND:
474 sizeof (struct NotifyTrafficMessage) +
475 sizeof (struct GNUNET_MessageHeader))
480 ntm = (const struct NotifyTrafficMessage *) msg;
481 em = (const struct GNUNET_MessageHeader *) &ntm[1];
483 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
484 "Received message of type %u and size %u from peer `%4s'\n",
487 GNUNET_i2s (&ntm->peer));
489 if ((GNUNET_NO == h->inbound_hdr_only) &&
490 (msize != ntohs (em->size) + sizeof (struct NotifyTrafficMessage)))
495 et = ntohs (em->type);
496 for (hpos = 0; hpos < h->hcnt; hpos++)
498 mh = &h->handlers[hpos];
501 if ((mh->expected_size != ntohs (em->size)) &&
502 (mh->expected_size != 0))
508 h->handlers[hpos].callback (h->cls, &ntm->peer, em,
509 GNUNET_TIME_relative_ntoh (ntm->latency),
510 ntohl (ntm->distance)))
512 /* error in processing, do not process other messages! */
516 if (NULL != h->inbound_notify)
517 h->inbound_notify (h->cls, &ntm->peer, em,
518 GNUNET_TIME_relative_ntoh (ntm->latency),
519 ntohl (ntm->distance));
521 case GNUNET_MESSAGE_TYPE_CORE_NOTIFY_OUTBOUND:
523 sizeof (struct NotifyTrafficMessage) +
524 sizeof (struct GNUNET_MessageHeader))
529 ntm = (const struct NotifyTrafficMessage *) msg;
530 em = (const struct GNUNET_MessageHeader *) &ntm[1];
531 if ((GNUNET_NO == h->outbound_hdr_only) &&
532 (msize != ntohs (em->size) + sizeof (struct NotifyTrafficMessage)))
537 if (NULL == h->outbound_notify)
542 h->outbound_notify (h->cls, &ntm->peer, em,
543 GNUNET_TIME_relative_ntoh (ntm->latency),
544 ntohl (ntm->distance));
550 GNUNET_CLIENT_receive (h->client_notifications,
551 &main_notify_handler, h, GNUNET_TIME_UNIT_FOREVER_REL);
556 * Function called when we are ready to transmit our
557 * "START" message (or when this operation timed out).
560 * @param size number of bytes available in buf
561 * @param buf where the callee should write the message
562 * @return number of bytes written to buf
564 static size_t transmit_start (void *cls, size_t size, void *buf);
568 * Function called on the first message received from
569 * the service (contains our public key, etc.).
570 * Should trigger calling the init callback
571 * and then start our regular message processing.
574 * @param msg message received, NULL on timeout or fatal error
577 init_reply_handler (void *cls, const struct GNUNET_MessageHeader *msg)
579 struct GNUNET_CORE_Handle *h = cls;
580 const struct InitReplyMessage *m;
581 GNUNET_CORE_StartupCallback init;
582 struct GNUNET_PeerIdentity my_identity;
585 (ntohs (msg->size) != sizeof (struct InitReplyMessage)) ||
586 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_CORE_INIT_REPLY))
590 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
592 ("Error connecting to core service (failed to receive `%s' message, got message of type %u and size %u).\n"),
601 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
602 _("Failed to connect to core service, will retry.\n"));
605 transmit_start (h, 0, NULL);
608 m = (const struct InitReplyMessage *) msg;
609 GNUNET_break (0 == ntohl (m->reserved));
610 /* start our message processing loop */
612 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
613 "Successfully connected to core service, starting processing loop.\n");
615 h->currently_down = GNUNET_NO;
616 trigger_next_request (h);
617 GNUNET_CLIENT_receive (h->client_notifications,
618 &main_notify_handler, h, GNUNET_TIME_UNIT_FOREVER_REL);
619 if (NULL != (init = h->init))
621 /* mark so we don't call init on reconnect */
623 GNUNET_CRYPTO_hash (&m->publicKey,
625 GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
626 &my_identity.hashPubKey);
627 init (h->cls, h, &my_identity, &m->publicKey);
633 reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
635 struct GNUNET_CORE_Handle *h = cls;
636 h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
642 * Function called when we are ready to transmit our
643 * "START" message (or when this operation timed out).
646 * @param size number of bytes available in buf
647 * @param buf where the callee should write the message
648 * @return number of bytes written to buf
651 transmit_start (void *cls, size_t size, void *buf)
653 struct GNUNET_CORE_Handle *h = cls;
654 struct InitMessage *init;
659 struct GNUNET_TIME_Relative delay;
664 if ((h->init == NULL) ||
665 (GNUNET_TIME_absolute_get ().abs_value < h->startup_timeout.abs_value))
667 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
668 _("Failed to connect to core service, retrying.\n"));
669 delay = GNUNET_TIME_absolute_get_remaining (h->startup_timeout);
670 if ((h->init == NULL) || (delay.rel_value > 1000))
671 delay = GNUNET_TIME_UNIT_SECONDS;
674 GNUNET_TIME_relative_to_absolute (GNUNET_TIME_UNIT_MINUTES);
676 GNUNET_SCHEDULER_add_delayed (delay, &reconnect_task, h);
679 /* timeout on initial connect */
680 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
681 _("Failed to connect to core service, giving up.\n"));
682 h->init (h->cls, NULL, NULL, NULL);
683 GNUNET_CORE_disconnect (h);
686 msize = h->hcnt * sizeof (uint16_t) + sizeof (struct InitMessage);
687 GNUNET_assert (size >= msize);
689 init->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_INIT);
690 init->header.size = htons (msize);
691 opt = GNUNET_CORE_OPTION_NOTHING;
692 if (h->connects != NULL)
693 opt |= GNUNET_CORE_OPTION_SEND_CONNECT;
694 if (h->disconnects != NULL)
695 opt |= GNUNET_CORE_OPTION_SEND_DISCONNECT;
696 if (h->status_events != NULL)
697 opt |= GNUNET_CORE_OPTION_SEND_STATUS_CHANGE;
698 if (h->inbound_notify != NULL)
700 if (h->inbound_hdr_only)
701 opt |= GNUNET_CORE_OPTION_SEND_HDR_INBOUND;
703 opt |= GNUNET_CORE_OPTION_SEND_FULL_INBOUND;
705 if (h->outbound_notify != NULL)
707 if (h->outbound_hdr_only)
708 opt |= GNUNET_CORE_OPTION_SEND_HDR_OUTBOUND;
710 opt |= GNUNET_CORE_OPTION_SEND_FULL_OUTBOUND;
712 init->options = htonl (opt);
713 ts = (uint16_t *) & init[1];
714 for (hpos = 0; hpos < h->hcnt; hpos++)
715 ts[hpos] = htons (h->handlers[hpos].type);
716 GNUNET_CLIENT_receive (h->client_notifications,
719 GNUNET_TIME_absolute_get_remaining
720 (h->startup_timeout));
721 return sizeof (struct InitMessage) + h->hcnt * sizeof (uint16_t);
726 * Connect to the core service. Note that the connection may
727 * complete (or fail) asynchronously.
729 * @param cfg configuration to use
730 * @param queue_size size of the per-peer message queue
731 * @param timeout after how long should we give up trying to connect to the core service?
732 * @param cls closure for the various callbacks that follow (including handlers in the handlers array)
733 * @param init callback to call on timeout or once we have successfully
734 * connected to the core service; note that timeout is only meaningful if init is not NULL
735 * @param connects function to call on peer connect, can be NULL
736 * @param disconnects function to call on peer disconnect / timeout, can be NULL
737 * @param status_events function to call on changes to peer connection status, can be NULL
738 * @param inbound_notify function to call for all inbound messages, can be NULL
739 * @param inbound_hdr_only set to GNUNET_YES if inbound_notify will only read the
740 * GNUNET_MessageHeader and hence we do not need to give it the full message;
741 * can be used to improve efficiency, ignored if inbound_notify is NULLL
742 * @param outbound_notify function to call for all outbound messages, can be NULL
743 * @param outbound_hdr_only set to GNUNET_YES if outbound_notify will only read the
744 * GNUNET_MessageHeader and hence we do not need to give it the full message
745 * can be used to improve efficiency, ignored if outbound_notify is NULLL
746 * @param handlers callbacks for messages we care about, NULL-terminated
747 * @return handle to the core service (only useful for disconnect until 'init' is called);
748 * NULL on error (in this case, init is never called)
750 struct GNUNET_CORE_Handle *
751 GNUNET_CORE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
752 unsigned int queue_size,
753 struct GNUNET_TIME_Relative timeout,
755 GNUNET_CORE_StartupCallback init,
756 GNUNET_CORE_ConnectEventHandler connects,
757 GNUNET_CORE_DisconnectEventHandler disconnects,
758 GNUNET_CORE_PeerStatusEventHandler status_events,
759 GNUNET_CORE_MessageCallback inbound_notify,
760 int inbound_hdr_only,
761 GNUNET_CORE_MessageCallback outbound_notify,
762 int outbound_hdr_only,
763 const struct GNUNET_CORE_MessageHandler *handlers)
765 struct GNUNET_CORE_Handle *h;
767 h = GNUNET_malloc (sizeof (struct GNUNET_CORE_Handle));
771 h->connects = connects;
772 h->disconnects = disconnects;
773 h->status_events = status_events;
774 h->inbound_notify = inbound_notify;
775 h->outbound_notify = outbound_notify;
776 h->inbound_hdr_only = inbound_hdr_only;
777 h->outbound_hdr_only = outbound_hdr_only;
778 h->handlers = handlers;
779 h->queue_size = queue_size;
780 h->client_notifications = GNUNET_CLIENT_connect ("core", cfg);
781 if (h->client_notifications == NULL)
786 h->startup_timeout = GNUNET_TIME_relative_to_absolute (timeout);
788 while (handlers[h->hcnt].callback != NULL)
790 GNUNET_assert (h->hcnt <
791 (GNUNET_SERVER_MAX_MESSAGE_SIZE -
792 sizeof (struct InitMessage)) / sizeof (uint16_t));
794 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
795 "Trying to connect to core service in next %llu ms.\n",
799 GNUNET_CLIENT_notify_transmit_ready (h->client_notifications,
800 sizeof (struct InitMessage) +
801 sizeof (uint16_t) * h->hcnt, timeout,
809 * Disconnect from the core service.
811 * @param handle connection to core to disconnect
814 GNUNET_CORE_disconnect (struct GNUNET_CORE_Handle *handle)
816 if (handle->cth != NULL)
817 GNUNET_CLIENT_notify_transmit_ready_cancel (handle->cth);
818 if (handle->solicit_transmit_req != NULL)
819 GNUNET_CORE_notify_transmit_ready_cancel (handle->solicit_transmit_req);
820 if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
821 GNUNET_SCHEDULER_cancel (handle->reconnect_task);
822 if (handle->client_notifications != NULL)
823 GNUNET_CLIENT_disconnect (handle->client_notifications, GNUNET_NO);
824 GNUNET_break (handle->pending_head == NULL);
825 GNUNET_free_non_null (handle->solicit_buffer);
826 GNUNET_free (handle);
831 * Build the message requesting data transmission.
834 produce_send (void *cls, size_t size, void *buf)
836 struct GNUNET_CORE_TransmitHandle *th = cls;
837 struct GNUNET_CORE_Handle *h;
838 struct SendMessage *sm;
840 GNUNET_CONNECTION_TransmitReadyNotify notify;
846 /* timeout or error */
848 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
849 "P2P transmission request for `%4s' timed out.\n",
850 GNUNET_i2s(&th->peer));
852 GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
853 GNUNET_CORE_notify_transmit_ready_cancel (th);
854 if ((h->pending_head == th) && (h->cth != NULL)) /* Request hasn't been canceled yet! */
856 GNUNET_CLIENT_notify_transmit_ready_cancel (h->cth);
858 trigger_next_request (h);
860 /* Otherwise this request timed out, but another is actually queued for sending, so don't try to send another! */
863 sm = (struct SendMessage *) buf;
864 sm->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_SEND);
865 sm->priority = htonl (th->priority);
866 sm->deadline = GNUNET_TIME_absolute_hton (th->timeout);
869 notify_cls = th->notify_cls;
870 GNUNET_CORE_notify_transmit_ready_cancel (th);
871 trigger_next_request (h);
872 size = GNUNET_MIN (size,
873 GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE);
874 GNUNET_assert (size >= sizeof (struct SendMessage));
875 dt = notify (notify_cls, size - sizeof (struct SendMessage), &sm[1]);
879 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
880 "Size of clients message to peer %s is 0!\n",
881 GNUNET_i2s(&sm->peer));
883 /* client decided to send nothing! */
887 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
888 "Produced SEND message to core with %u bytes payload\n",
891 GNUNET_assert (dt >= sizeof (struct GNUNET_MessageHeader));
892 if (dt + sizeof (struct SendMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
898 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
899 "Preparing for P2P transmission of %u bytes to `%4s'.\n",
901 GNUNET_i2s(&sm->peer));
903 sm->header.size = htons (dt + sizeof (struct SendMessage));
904 GNUNET_assert (dt + sizeof (struct SendMessage) <= size);
905 return dt + sizeof (struct SendMessage);
910 * Ask the core to call "notify" once it is ready to transmit the
911 * given number of bytes to the specified "target". If we are not yet
912 * connected to the specified peer, a call to this function will cause
913 * us to try to establish a connection.
915 * @param handle connection to core service
916 * @param priority how important is the message?
917 * @param maxdelay how long can the message wait?
918 * @param target who should receive the message,
919 * use NULL for this peer (loopback)
920 * @param notify_size how many bytes of buffer space does notify want?
921 * @param notify function to call when buffer space is available
922 * @param notify_cls closure for notify
923 * @return non-NULL if the notify callback was queued,
924 * NULL if we can not even queue the request (insufficient
925 * memory); if NULL is returned, "notify" will NOT be called.
927 struct GNUNET_CORE_TransmitHandle *
928 GNUNET_CORE_notify_transmit_ready (struct GNUNET_CORE_Handle *handle,
929 unsigned int priority,
930 struct GNUNET_TIME_Relative maxdelay,
931 const struct GNUNET_PeerIdentity *target,
933 GNUNET_CONNECTION_TransmitReadyNotify notify,
936 struct GNUNET_CORE_TransmitHandle *th;
938 GNUNET_assert (notify_size + sizeof (struct SendMessage) <
939 GNUNET_SERVER_MAX_MESSAGE_SIZE);
940 th = GNUNET_malloc (sizeof (struct GNUNET_CORE_TransmitHandle));
942 GNUNET_CONTAINER_DLL_insert_after (handle->pending_head,
943 handle->pending_tail,
944 handle->pending_tail,
946 th->get_message = &produce_send;
947 th->get_message_cls = th;
949 th->notify_cls = notify_cls;
951 th->timeout = GNUNET_TIME_relative_to_absolute (maxdelay);
952 th->timeout_task = GNUNET_SCHEDULER_add_delayed (maxdelay,
953 &timeout_request, th);
954 th->priority = priority;
955 th->msize = sizeof (struct SendMessage) + notify_size;
956 /* was the request queue previously empty? */
957 if ( (handle->pending_head == th) &&
958 (handle->cth == NULL) )
959 trigger_next_request (handle);
965 * Cancel the specified transmission-ready notification.
967 * @param th handle that was returned by "notify_transmit_ready".
970 GNUNET_CORE_notify_transmit_ready_cancel (struct GNUNET_CORE_TransmitHandle
973 struct GNUNET_CORE_Handle *h = th->ch;
975 if (h->submitted == th)
978 GNUNET_CONTAINER_DLL_remove (h->pending_head,
981 if (th->timeout_task != GNUNET_SCHEDULER_NO_TASK)
982 GNUNET_SCHEDULER_cancel (th->timeout_task);
987 /* end of core_api.c */