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3 Copyright (C) 2009-2016 GNUnet e.V.
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6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
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11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Affero General Public License for more details.
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
18 SPDX-License-Identifier: AGPL3.0-or-later
21 * @file core/core_api.c
22 * @brief core service; this is the main API for encrypted P2P
24 * @author Christian Grothoff
27 #include "gnunet_util_lib.h"
28 #include "gnunet_constants.h"
29 #include "gnunet_core_service.h"
32 #define LOG(kind,...) GNUNET_log_from (kind, "core-api",__VA_ARGS__)
36 * Information we track for each peer.
42 * Corresponding CORE handle.
44 struct GNUNET_CORE_Handle *h;
47 * Message queue for the peer.
49 struct GNUNET_MQ_Handle *mq;
52 * Message we are currently trying to pass to the CORE service
53 * for this peer (from @e mq).
55 struct GNUNET_MQ_Envelope *env;
58 * Value the client returned when we connected, used
59 * as the closure in various places.
64 * Peer the record is about.
66 struct GNUNET_PeerIdentity peer;
69 * SendMessageRequest ID generator for this peer.
77 * Context for the core service connection.
79 struct GNUNET_CORE_Handle
83 * Configuration we're using.
85 const struct GNUNET_CONFIGURATION_Handle *cfg;
88 * Closure for the various callbacks.
93 * Function to call once we've handshaked with the core service.
95 GNUNET_CORE_StartupCallback init;
98 * Function to call whenever we're notified about a peer connecting.
100 GNUNET_CORE_ConnectEventHandler connects;
103 * Function to call whenever we're notified about a peer disconnecting.
105 GNUNET_CORE_DisconnectEventHandler disconnects;
108 * Function handlers for messages of particular type.
110 struct GNUNET_MQ_MessageHandler *handlers;
113 * Our message queue for transmissions to the service.
115 struct GNUNET_MQ_Handle *mq;
118 * Hash map listing all of the peers that we are currently
121 struct GNUNET_CONTAINER_MultiPeerMap *peers;
124 * Identity of this peer.
126 struct GNUNET_PeerIdentity me;
129 * ID of reconnect task (if any).
131 struct GNUNET_SCHEDULER_Task *reconnect_task;
134 * Current delay we use for re-trying to connect to core.
136 struct GNUNET_TIME_Relative retry_backoff;
139 * Number of entries in the handlers array.
144 * Did we ever get INIT?
152 * Our current client connection went down. Clean it up
153 * and try to reconnect!
155 * @param h our handle to the core service
158 reconnect (struct GNUNET_CORE_Handle *h);
162 * Task schedule to try to re-connect to core.
164 * @param cls the `struct GNUNET_CORE_Handle`
165 * @param tc task context
168 reconnect_task (void *cls)
170 struct GNUNET_CORE_Handle *h = cls;
172 h->reconnect_task = NULL;
173 LOG (GNUNET_ERROR_TYPE_DEBUG,
174 "Connecting to CORE service after delay\n");
180 * Notify clients about disconnect and free the entry for connected
183 * @param cls the `struct GNUNET_CORE_Handle *`
184 * @param key the peer identity (not used)
185 * @param value the `struct PeerRecord` to free.
186 * @return #GNUNET_YES (continue)
189 disconnect_and_free_peer_entry (void *cls,
190 const struct GNUNET_PeerIdentity *key,
193 struct GNUNET_CORE_Handle *h = cls;
194 struct PeerRecord *pr = value;
196 GNUNET_assert (pr->h == h);
197 if (NULL != h->disconnects)
198 h->disconnects (h->cls,
201 GNUNET_assert (GNUNET_YES ==
202 GNUNET_CONTAINER_multipeermap_remove (h->peers,
205 GNUNET_MQ_destroy (pr->mq);
206 GNUNET_assert (NULL == pr->mq);
209 GNUNET_MQ_discard (pr->env);
218 * Close down any existing connection to the CORE service and
219 * try re-establishing it later.
221 * @param h our handle
224 reconnect_later (struct GNUNET_CORE_Handle *h)
226 GNUNET_assert (NULL == h->reconnect_task);
229 GNUNET_MQ_destroy (h->mq);
232 GNUNET_assert (NULL == h->reconnect_task);
234 GNUNET_SCHEDULER_add_delayed (h->retry_backoff,
237 GNUNET_CONTAINER_multipeermap_iterate (h->peers,
238 &disconnect_and_free_peer_entry,
240 h->retry_backoff = GNUNET_TIME_STD_BACKOFF (h->retry_backoff);
245 * Error handler for the message queue to the CORE service.
246 * On errors, we reconnect.
248 * @param cls closure, a `struct GNUNET_CORE_Handle *`
249 * @param error error code
252 handle_mq_error (void *cls,
253 enum GNUNET_MQ_Error error)
255 struct GNUNET_CORE_Handle *h = cls;
257 LOG (GNUNET_ERROR_TYPE_DEBUG,
265 * Inquire with CORE what options should be set for a message
266 * so that it is transmitted with the given @a priority and
267 * the given @a cork value.
269 * @param cork desired corking
270 * @param priority desired message priority
271 * @param[out] flags set to `flags` value for #GNUNET_MQ_set_options()
272 * @return `extra` argument to give to #GNUNET_MQ_set_options()
275 GNUNET_CORE_get_mq_options (int cork,
276 enum GNUNET_CORE_Priority priority,
279 *flags = ((uint64_t) priority) + (((uint64_t) cork) << 32);
285 * Implement sending functionality of a message queue for
286 * us sending messages to a peer.
288 * @param mq the message queue
289 * @param msg the message to send
290 * @param impl_state state of the implementation
293 core_mq_send_impl (struct GNUNET_MQ_Handle *mq,
294 const struct GNUNET_MessageHeader *msg,
297 struct PeerRecord *pr = impl_state;
298 struct GNUNET_CORE_Handle *h = pr->h;
299 struct SendMessageRequest *smr;
300 struct SendMessage *sm;
301 struct GNUNET_MQ_Envelope *env;
305 enum GNUNET_CORE_Priority priority;
309 /* We're currently reconnecting, pretend this worked */
310 GNUNET_MQ_impl_send_continue (mq);
313 GNUNET_assert (NULL == pr->env);
314 /* extract options from envelope */
315 env = GNUNET_MQ_get_current_envelope (mq);
316 GNUNET_break (NULL ==
317 GNUNET_MQ_env_get_options (env,
319 cork = (int) (flags >> 32);
320 priority = (uint32_t) flags;
322 /* check message size for sanity */
323 msize = ntohs (msg->size);
324 if (msize >= GNUNET_MAX_MESSAGE_SIZE - sizeof (struct SendMessage))
327 GNUNET_MQ_impl_send_continue (mq);
331 /* ask core for transmission */
332 LOG (GNUNET_ERROR_TYPE_DEBUG,
333 "Asking core for transmission of %u bytes to `%s'\n",
334 (unsigned int) msize,
335 GNUNET_i2s (&pr->peer));
336 env = GNUNET_MQ_msg (smr,
337 GNUNET_MESSAGE_TYPE_CORE_SEND_REQUEST);
338 smr->priority = htonl ((uint32_t) priority);
339 smr->peer = pr->peer;
340 smr->reserved = htonl (0);
341 smr->size = htons (msize);
342 smr->smr_id = htons (++pr->smr_id_gen);
343 GNUNET_MQ_send (h->mq,
346 /* prepare message with actual transmission data */
347 pr->env = GNUNET_MQ_msg_nested_mh (sm,
348 GNUNET_MESSAGE_TYPE_CORE_SEND,
350 sm->priority = htonl ((uint32_t) priority);
352 sm->cork = htonl ((uint32_t) cork);
353 sm->reserved = htonl (0);
354 LOG (GNUNET_ERROR_TYPE_DEBUG,
355 "Calling get_message with buffer of %u bytes (%s)\n",
356 (unsigned int) msize,
357 cork ? "corked" : "uncorked");
362 * Handle destruction of a message queue. Implementations must not
363 * free @a mq, but should take care of @a impl_state.
365 * @param mq the message queue to destroy
366 * @param impl_state state of the implementation
369 core_mq_destroy_impl (struct GNUNET_MQ_Handle *mq,
372 struct PeerRecord *pr = impl_state;
374 GNUNET_assert (mq == pr->mq);
380 * Implementation function that cancels the currently sent message.
381 * Should basically undo whatever #mq_send_impl() did.
383 * @param mq message queue
384 * @param impl_state state specific to the implementation
387 core_mq_cancel_impl (struct GNUNET_MQ_Handle *mq,
390 struct PeerRecord *pr = impl_state;
392 GNUNET_assert (NULL != pr->env);
393 GNUNET_MQ_discard (pr->env);
399 * We had an error processing a message we forwarded from a peer to
400 * the CORE service. We should just complain about it but otherwise
401 * continue processing.
404 * @param error error code
407 core_mq_error_handler (void *cls,
408 enum GNUNET_MQ_Error error)
410 /* struct PeerRecord *pr = cls; */
417 * Add the given peer to the list of our connected peers
418 * and create the respective data structures and notify
421 * @param h the core handle
422 * @param peer the peer that is connecting to us
425 connect_peer (struct GNUNET_CORE_Handle *h,
426 const struct GNUNET_PeerIdentity *peer)
428 struct PeerRecord *pr;
432 pr = GNUNET_new (struct PeerRecord);
435 GNUNET_assert (GNUNET_YES ==
436 GNUNET_CONTAINER_multipeermap_put (h->peers,
439 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
440 pr->mq = GNUNET_MQ_queue_for_callbacks (&core_mq_send_impl,
441 &core_mq_destroy_impl,
442 &core_mq_cancel_impl,
445 &core_mq_error_handler,
447 /* get our default options */
448 extra = GNUNET_CORE_get_mq_options (GNUNET_NO,
449 GNUNET_CORE_PRIO_BEST_EFFORT,
451 GNUNET_MQ_set_options (pr->mq,
454 if (NULL != h->connects)
456 pr->client_cls = h->connects (h->cls,
459 GNUNET_MQ_set_handlers_closure (pr->mq,
466 * Handle init reply message received from CORE service. Notify
467 * application that we are now connected to the CORE. Also fake
468 * loopback connection.
470 * @param cls the `struct GNUNET_CORE_Handle`
471 * @param m the init reply
474 handle_init_reply (void *cls,
475 const struct InitReplyMessage *m)
477 struct GNUNET_CORE_Handle *h = cls;
478 GNUNET_CORE_StartupCallback init;
480 GNUNET_break (0 == ntohl (m->reserved));
481 h->retry_backoff = GNUNET_TIME_UNIT_MILLISECONDS;
482 if (NULL != (init = h->init))
484 /* mark so we don't call init on reconnect */
486 h->me = m->my_identity;
487 LOG (GNUNET_ERROR_TYPE_DEBUG,
488 "Connected to core service of peer `%s'.\n",
489 GNUNET_i2s (&h->me));
490 h->have_init = GNUNET_YES;
496 LOG (GNUNET_ERROR_TYPE_DEBUG,
497 "Successfully reconnected to core service.\n");
498 if (GNUNET_NO == h->have_init)
500 h->me = m->my_identity;
501 h->have_init = GNUNET_YES;
505 GNUNET_break (0 == memcmp (&h->me,
507 sizeof (struct GNUNET_PeerIdentity)));
510 /* fake 'connect to self' */
517 * Handle connect message received from CORE service.
518 * Notify the application about the new connection.
520 * @param cls the `struct GNUNET_CORE_Handle`
521 * @param cnm the connect message
524 handle_connect_notify (void *cls,
525 const struct ConnectNotifyMessage *cnm)
527 struct GNUNET_CORE_Handle *h = cls;
528 struct PeerRecord *pr;
530 LOG (GNUNET_ERROR_TYPE_DEBUG,
531 "Received notification about connection from `%s'.\n",
532 GNUNET_i2s (&cnm->peer));
533 if (0 == memcmp (&h->me,
535 sizeof (struct GNUNET_PeerIdentity)))
537 /* connect to self!? */
541 pr = GNUNET_CONTAINER_multipeermap_get (h->peers,
555 * Handle disconnect message received from CORE service.
556 * Notify the application about the lost connection.
558 * @param cls the `struct GNUNET_CORE_Handle`
559 * @param dnm message about the disconnect event
562 handle_disconnect_notify (void *cls,
563 const struct DisconnectNotifyMessage *dnm)
565 struct GNUNET_CORE_Handle *h = cls;
566 struct PeerRecord *pr;
568 if (0 == memcmp (&h->me,
570 sizeof (struct GNUNET_PeerIdentity)))
572 /* disconnect from self!? */
576 GNUNET_break (0 == ntohl (dnm->reserved));
577 LOG (GNUNET_ERROR_TYPE_DEBUG,
578 "Received notification about disconnect from `%s'.\n",
579 GNUNET_i2s (&dnm->peer));
580 pr = GNUNET_CONTAINER_multipeermap_get (h->peers,
588 disconnect_and_free_peer_entry (h,
595 * Check that message received from CORE service is well-formed.
597 * @param cls the `struct GNUNET_CORE_Handle`
598 * @param ntm the message we got
599 * @return #GNUNET_OK if the message is well-formed
602 check_notify_inbound (void *cls,
603 const struct NotifyTrafficMessage *ntm)
606 const struct GNUNET_MessageHeader *em;
608 msize = ntohs (ntm->header.size) - sizeof (struct NotifyTrafficMessage);
609 if (msize < sizeof (struct GNUNET_MessageHeader))
612 return GNUNET_SYSERR;
614 em = (const struct GNUNET_MessageHeader *) &ntm[1];
615 if (msize != ntohs (em->size))
618 return GNUNET_SYSERR;
625 * Handle inbound message received from CORE service. If applicable,
626 * notify the application.
628 * @param cls the `struct GNUNET_CORE_Handle`
629 * @param ntm the message we got from CORE.
632 handle_notify_inbound (void *cls,
633 const struct NotifyTrafficMessage *ntm)
635 struct GNUNET_CORE_Handle *h = cls;
636 const struct GNUNET_MessageHeader *em;
637 struct PeerRecord *pr;
639 LOG (GNUNET_ERROR_TYPE_DEBUG,
640 "Received inbound message from `%s'.\n",
641 GNUNET_i2s (&ntm->peer));
642 em = (const struct GNUNET_MessageHeader *) &ntm[1];
643 pr = GNUNET_CONTAINER_multipeermap_get (h->peers,
651 GNUNET_MQ_inject_message (pr->mq,
657 * Handle message received from CORE service notifying us that we are
658 * now allowed to send a message to a peer. If that message is still
659 * pending, put it into the queue to be transmitted.
661 * @param cls the `struct GNUNET_CORE_Handle`
662 * @param smr the message we got
665 handle_send_ready (void *cls,
666 const struct SendMessageReady *smr)
668 struct GNUNET_CORE_Handle *h = cls;
669 struct PeerRecord *pr;
671 pr = GNUNET_CONTAINER_multipeermap_get (h->peers,
679 LOG (GNUNET_ERROR_TYPE_DEBUG,
680 "Received notification about transmission readiness to `%s'.\n",
681 GNUNET_i2s (&smr->peer));
684 /* request must have been cancelled between the original request
685 * and the response from CORE, ignore CORE's readiness */
688 if (ntohs (smr->smr_id) != pr->smr_id_gen)
690 /* READY message is for expired or cancelled message,
691 * ignore! (we should have already sent another request) */
695 /* ok, all good, send message out! */
696 GNUNET_MQ_send (h->mq,
699 GNUNET_MQ_impl_send_continue (pr->mq);
704 * Our current client connection went down. Clean it up and try to
707 * @param h our handle to the core service
710 reconnect (struct GNUNET_CORE_Handle *h)
712 struct GNUNET_MQ_MessageHandler handlers[] = {
713 GNUNET_MQ_hd_fixed_size (init_reply,
714 GNUNET_MESSAGE_TYPE_CORE_INIT_REPLY,
715 struct InitReplyMessage,
717 GNUNET_MQ_hd_fixed_size (connect_notify,
718 GNUNET_MESSAGE_TYPE_CORE_NOTIFY_CONNECT,
719 struct ConnectNotifyMessage,
721 GNUNET_MQ_hd_fixed_size (disconnect_notify,
722 GNUNET_MESSAGE_TYPE_CORE_NOTIFY_DISCONNECT,
723 struct DisconnectNotifyMessage,
725 GNUNET_MQ_hd_var_size (notify_inbound,
726 GNUNET_MESSAGE_TYPE_CORE_NOTIFY_INBOUND,
727 struct NotifyTrafficMessage,
729 GNUNET_MQ_hd_fixed_size (send_ready,
730 GNUNET_MESSAGE_TYPE_CORE_SEND_READY,
731 struct SendMessageReady,
733 GNUNET_MQ_handler_end ()
735 struct InitMessage *init;
736 struct GNUNET_MQ_Envelope *env;
739 GNUNET_assert (NULL == h->mq);
740 h->mq = GNUNET_CLIENT_connect (h->cfg,
750 env = GNUNET_MQ_msg_extra (init,
751 sizeof (uint16_t) * h->hcnt,
752 GNUNET_MESSAGE_TYPE_CORE_INIT);
753 LOG (GNUNET_ERROR_TYPE_INFO,
754 "(Re)connecting to CORE service\n");
755 init->options = htonl (0);
756 ts = (uint16_t *) &init[1];
757 for (unsigned int hpos = 0; hpos < h->hcnt; hpos++)
758 ts[hpos] = htons (h->handlers[hpos].type);
759 GNUNET_MQ_send (h->mq,
765 * Connect to the core service. Note that the connection may complete
766 * (or fail) asynchronously.
768 * @param cfg configuration to use
769 * @param cls closure for the various callbacks that follow (including handlers in the handlers array)
770 * @param init callback to call once we have successfully
771 * connected to the core service
772 * @param connects function to call on peer connect, can be NULL
773 * @param disconnects function to call on peer disconnect / timeout, can be NULL
774 * @param handlers callbacks for messages we care about, NULL-terminated
775 * @return handle to the core service (only useful for disconnect until @a init is called);
776 * NULL on error (in this case, init is never called)
778 struct GNUNET_CORE_Handle *
779 GNUNET_CORE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
781 GNUNET_CORE_StartupCallback init,
782 GNUNET_CORE_ConnectEventHandler connects,
783 GNUNET_CORE_DisconnectEventHandler disconnects,
784 const struct GNUNET_MQ_MessageHandler *handlers)
786 struct GNUNET_CORE_Handle *h;
788 h = GNUNET_new (struct GNUNET_CORE_Handle);
792 h->connects = connects;
793 h->disconnects = disconnects;
794 h->peers = GNUNET_CONTAINER_multipeermap_create (128,
796 h->handlers = GNUNET_MQ_copy_handlers (handlers);
797 h->hcnt = GNUNET_MQ_count_handlers (handlers);
798 GNUNET_assert (h->hcnt <
799 (GNUNET_MAX_MESSAGE_SIZE -
800 sizeof (struct InitMessage)) / sizeof (uint16_t));
801 LOG (GNUNET_ERROR_TYPE_DEBUG,
802 "Connecting to CORE service\n");
806 GNUNET_CORE_disconnect (h);
814 * Disconnect from the core service.
816 * @param handle connection to core to disconnect
819 GNUNET_CORE_disconnect (struct GNUNET_CORE_Handle *handle)
821 LOG (GNUNET_ERROR_TYPE_DEBUG,
822 "Disconnecting from CORE service\n");
823 GNUNET_CONTAINER_multipeermap_iterate (handle->peers,
824 &disconnect_and_free_peer_entry,
826 GNUNET_CONTAINER_multipeermap_destroy (handle->peers);
827 handle->peers = NULL;
828 if (NULL != handle->reconnect_task)
830 GNUNET_SCHEDULER_cancel (handle->reconnect_task);
831 handle->reconnect_task = NULL;
833 if (NULL != handle->mq)
835 GNUNET_MQ_destroy (handle->mq);
838 GNUNET_free_non_null (handle->handlers);
839 GNUNET_free (handle);
844 * Obtain the message queue for a connected peer.
846 * @param h the core handle
847 * @param pid the identity of the peer to check if it has been connected to us
848 * @return NULL if peer is not connected
850 struct GNUNET_MQ_Handle *
851 GNUNET_CORE_get_mq (const struct GNUNET_CORE_Handle *h,
852 const struct GNUNET_PeerIdentity *pid)
854 struct PeerRecord *pr;
856 pr = GNUNET_CONTAINER_multipeermap_get (h->peers,
864 /* end of core_api.c */