2 This file is part of GNUnet.
3 (C) 2012, 2013 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.
23 * @brief api for the set service
24 * @author Florian Dold
27 #include "gnunet_util_lib.h"
28 #include "gnunet_protocols.h"
29 #include "gnunet_client_lib.h"
30 #include "gnunet_set_service.h"
34 #define LOG(kind,...) GNUNET_log_from (kind, "set-api",__VA_ARGS__)
37 * Opaque handle to a set.
39 struct GNUNET_SET_Handle
42 * Client connected to the set service.
44 struct GNUNET_CLIENT_Connection *client;
47 * Message queue for 'client'.
49 struct GNUNET_MQ_Handle *mq;
52 * Linked list of operations on the set.
54 struct GNUNET_SET_OperationHandle *ops_head;
57 * Linked list of operations on the set.
59 struct GNUNET_SET_OperationHandle *ops_tail;
62 * Should the set be destroyed once all operations are gone?
64 int destroy_requested;
67 * Has the set become invalid (e.g. service died)?
72 * Callback for the current iteration over the set,
73 * NULL if no iterator is active.
75 GNUNET_SET_ElementIterator iterator;
78 * Closure for 'iterator'
85 * Opaque handle to a set operation request from another peer.
87 struct GNUNET_SET_Request
90 * Id of the request, used to identify the request when
91 * accepting/rejecting it.
96 * Has the request been accepted already?
97 * GNUNET_YES/GNUNET_NO
104 * Handle to an operation.
105 * Only known to the service after commiting
106 * the handle with a set.
108 struct GNUNET_SET_OperationHandle
111 * Function to be called when we have a result,
114 GNUNET_SET_ResultIterator result_cb;
117 * Closure for result_cb.
122 * Local set used for the operation,
123 * NULL if no set has been provided by conclude yet.
125 struct GNUNET_SET_Handle *set;
128 * Request ID to identify the operation within the set.
133 * Message sent to the server on calling conclude,
134 * NULL if conclude has been called.
136 struct GNUNET_MQ_Envelope *conclude_mqm;
139 * Address of the request if in the conclude message,
140 * used to patch the request id into the message when the set is known.
142 uint32_t *request_id_addr;
145 * Handles are kept in a linked list.
147 struct GNUNET_SET_OperationHandle *prev;
150 * Handles are kept in a linked list.
152 struct GNUNET_SET_OperationHandle *next;
157 * Opaque handle to a listen operation.
159 struct GNUNET_SET_ListenHandle
162 * Connection to the service.
164 struct GNUNET_CLIENT_Connection *client;
167 * Message queue for the client.
169 struct GNUNET_MQ_Handle* mq;
172 * Function to call on a new incoming request,
175 GNUNET_SET_ListenCallback listen_cb;
178 * Closure for listen_cb.
185 * Handle element for iteration over the set.
188 * @param mh the message
191 handle_iter_element (void *cls, const struct GNUNET_MessageHeader *mh)
193 struct GNUNET_SET_Handle *set = cls;
194 struct GNUNET_SET_Element element;
195 const struct GNUNET_SET_IterResponseMessage *msg =
196 (const struct GNUNET_SET_IterResponseMessage *) mh;
198 if (NULL == set->iterator)
201 element.type = htons (mh->type);
202 element.data = &msg[1];
203 set->iterator (set->iterator_cls, &element);
208 * Handle element for iteration over the set.
211 * @param mh the message
214 handle_iter_done (void *cls, const struct GNUNET_MessageHeader *mh)
216 struct GNUNET_SET_Handle *set = cls;
218 if (NULL == set->iterator)
221 set->iterator (set->iterator_cls, NULL);
226 * Handle result message for a set operation.
229 * @param mh the message
232 handle_result (void *cls, const struct GNUNET_MessageHeader *mh)
234 const struct GNUNET_SET_ResultMessage *msg;
235 struct GNUNET_SET_Handle *set = cls;
236 struct GNUNET_SET_OperationHandle *oh;
237 struct GNUNET_SET_Element e;
238 enum GNUNET_SET_Status result_status;
240 msg = (const struct GNUNET_SET_ResultMessage *) mh;
241 GNUNET_assert (NULL != set);
242 GNUNET_assert (NULL != set->mq);
244 result_status = ntohs (msg->result_status);
246 oh = GNUNET_MQ_assoc_get (set->mq, ntohl (msg->request_id));
247 GNUNET_assert (NULL != oh);
248 /* status is not STATUS_OK => there's no attached element,
249 * and this is the last result message we get */
250 if (GNUNET_SET_STATUS_OK != result_status)
252 GNUNET_MQ_assoc_remove (set->mq, ntohl (msg->request_id));
253 GNUNET_CONTAINER_DLL_remove (oh->set->ops_head, oh->set->ops_tail, oh);
254 if (GNUNET_YES == oh->set->destroy_requested)
255 GNUNET_SET_destroy (oh->set);
256 if (NULL != oh->result_cb)
257 oh->result_cb (oh->result_cls, NULL, result_status);
263 e.size = ntohs (mh->size) - sizeof (struct GNUNET_SET_ResultMessage);
264 e.type = msg->element_type;
265 if (NULL != oh->result_cb)
266 oh->result_cb (oh->result_cls, &e, result_status);
270 * Handle request message for a listen operation
272 * @param cls the listen handle
273 * @param mh the message
276 handle_request (void *cls, const struct GNUNET_MessageHeader *mh)
278 struct GNUNET_SET_RequestMessage *msg = (struct GNUNET_SET_RequestMessage *) mh;
279 struct GNUNET_SET_ListenHandle *lh = cls;
280 struct GNUNET_SET_Request *req;
281 struct GNUNET_MessageHeader *context_msg;
283 LOG (GNUNET_ERROR_TYPE_DEBUG, "processing operation request\n");
284 req = GNUNET_new (struct GNUNET_SET_Request);
285 req->accept_id = ntohl (msg->accept_id);
286 context_msg = GNUNET_MQ_extract_nested_mh (msg);
287 /* calling GNUNET_SET_accept in the listen cb will set req->accepted */
288 lh->listen_cb (lh->listen_cls, &msg->peer_id, context_msg, req);
290 if (GNUNET_NO == req->accepted)
292 struct GNUNET_MQ_Envelope *mqm;
293 struct GNUNET_SET_AcceptRejectMessage *amsg;
295 mqm = GNUNET_MQ_msg (amsg, GNUNET_MESSAGE_TYPE_SET_REJECT);
296 /* no request id, as we refused */
297 amsg->request_id = htonl (0);
298 amsg->accept_reject_id = msg->accept_id;
299 GNUNET_MQ_send (lh->mq, mqm);
301 LOG (GNUNET_ERROR_TYPE_DEBUG, "rejecting request\n");
304 LOG (GNUNET_ERROR_TYPE_DEBUG, "processed op request from service\n");
306 /* the accept-case is handled in GNUNET_SET_accept,
307 * as we have the accept message available there */
312 handle_client_listener_error (void *cls, enum GNUNET_MQ_Error error)
314 struct GNUNET_SET_ListenHandle *lh = cls;
316 lh->listen_cb (lh->listen_cls, NULL, NULL, NULL);
321 handle_client_set_error (void *cls, enum GNUNET_MQ_Error error)
323 struct GNUNET_SET_Handle *set = cls;
325 while (NULL != set->ops_head)
327 if (NULL != set->ops_head->result_cb)
328 set->ops_head->result_cb (set->ops_head->result_cls, NULL,
329 GNUNET_SET_STATUS_FAILURE);
330 GNUNET_SET_operation_cancel (set->ops_head);
333 set->invalid = GNUNET_YES;
338 * Create an empty set, supporting the specified operation.
340 * @param cfg configuration to use for connecting to the
342 * @param op operation supported by the set
343 * Note that the operation has to be specified
344 * beforehand, as certain set operations need to maintain
345 * data structures spefific to the operation
346 * @return a handle to the set
348 struct GNUNET_SET_Handle *
349 GNUNET_SET_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
350 enum GNUNET_SET_OperationType op)
352 struct GNUNET_SET_Handle *set;
353 struct GNUNET_MQ_Envelope *mqm;
354 struct GNUNET_SET_CreateMessage *msg;
355 static const struct GNUNET_MQ_MessageHandler mq_handlers[] = {
356 {handle_result, GNUNET_MESSAGE_TYPE_SET_RESULT, 0},
357 {handle_iter_element, GNUNET_MESSAGE_TYPE_SET_ITER_ELEMENT, 0},
358 {handle_iter_done, GNUNET_MESSAGE_TYPE_SET_ITER_DONE, 0},
359 GNUNET_MQ_HANDLERS_END
362 set = GNUNET_new (struct GNUNET_SET_Handle);
363 set->client = GNUNET_CLIENT_connect ("set", cfg);
364 LOG (GNUNET_ERROR_TYPE_DEBUG, "set client created\n");
365 GNUNET_assert (NULL != set->client);
366 set->mq = GNUNET_MQ_queue_for_connection_client (set->client, mq_handlers,
367 handle_client_set_error, set);
368 GNUNET_assert (NULL != set->mq);
369 mqm = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_SET_CREATE);
370 msg->operation = htons (op);
371 GNUNET_MQ_send (set->mq, mqm);
377 * Add an element to the given set.
378 * After the element has been added (in the sense of being
379 * transmitted to the set service), cont will be called.
380 * Calls to add_element can be queued
382 * @param set set to add element to
383 * @param element element to add to the set
384 * @param cont continuation called after the element has been added
385 * @param cont_cls closure for cont
386 * @return GNUNET_OK on success, GNUNET_SYSERR if the
387 * set is invalid (e.g. the set service crashed)
390 GNUNET_SET_add_element (struct GNUNET_SET_Handle *set,
391 const struct GNUNET_SET_Element *element,
392 GNUNET_SET_Continuation cont,
395 struct GNUNET_MQ_Envelope *mqm;
396 struct GNUNET_SET_ElementMessage *msg;
398 if (GNUNET_YES == set->invalid)
402 return GNUNET_SYSERR;
405 mqm = GNUNET_MQ_msg_extra (msg, element->size, GNUNET_MESSAGE_TYPE_SET_ADD);
406 msg->element_type = element->type;
407 memcpy (&msg[1], element->data, element->size);
408 GNUNET_MQ_notify_sent (mqm, cont, cont_cls);
409 GNUNET_MQ_send (set->mq, mqm);
415 * Remove an element to the given set.
416 * After the element has been removed (in the sense of the
417 * request being transmitted to the set service), cont will be called.
418 * Calls to remove_element can be queued
420 * @param set set to remove element from
421 * @param element element to remove from the set
422 * @param cont continuation called after the element has been removed
423 * @param cont_cls closure for cont
424 * @return GNUNET_OK on success, GNUNET_SYSERR if the
425 * set is invalid (e.g. the set service crashed)
428 GNUNET_SET_remove_element (struct GNUNET_SET_Handle *set,
429 const struct GNUNET_SET_Element *element,
430 GNUNET_SET_Continuation cont,
433 struct GNUNET_MQ_Envelope *mqm;
434 struct GNUNET_SET_ElementMessage *msg;
436 if (GNUNET_YES == set->invalid)
440 return GNUNET_SYSERR;
443 mqm = GNUNET_MQ_msg_extra (msg, element->size, GNUNET_MESSAGE_TYPE_SET_REMOVE);
444 msg->element_type = element->type;
445 memcpy (&msg[1], element->data, element->size);
446 GNUNET_MQ_notify_sent (mqm, cont, cont_cls);
447 GNUNET_MQ_send (set->mq, mqm);
453 * Destroy the set handle, and free all associated resources.
456 GNUNET_SET_destroy (struct GNUNET_SET_Handle *set)
458 if (NULL != set->ops_head)
460 set->destroy_requested = GNUNET_YES;
463 GNUNET_CLIENT_disconnect (set->client);
465 GNUNET_MQ_destroy (set->mq);
471 * Prepare a set operation to be evaluated with another peer.
472 * The evaluation will not start until the client provides
473 * a local set with GNUNET_SET_commit.
475 * @param other_peer peer with the other set
476 * @param app_id hash for the application using the set
477 * @param context_msg additional information for the request
478 * @param salt salt used for the set operation; sometimes set operations
479 * fail due to hash collisions, using a different salt for each operation
480 * makes it harder for an attacker to exploit this
481 * @param result_mode specified how results will be returned,
482 * see 'GNUNET_SET_ResultMode'.
483 * @param result_cb called on error or success
484 * @param result_cls closure for result_cb
485 * @return a handle to cancel the operation
487 struct GNUNET_SET_OperationHandle *
488 GNUNET_SET_prepare (const struct GNUNET_PeerIdentity *other_peer,
489 const struct GNUNET_HashCode *app_id,
490 const struct GNUNET_MessageHeader *context_msg,
492 enum GNUNET_SET_ResultMode result_mode,
493 GNUNET_SET_ResultIterator result_cb,
496 struct GNUNET_MQ_Envelope *mqm;
497 struct GNUNET_SET_OperationHandle *oh;
498 struct GNUNET_SET_EvaluateMessage *msg;
500 oh = GNUNET_new (struct GNUNET_SET_OperationHandle);
501 oh->result_cb = result_cb;
502 oh->result_cls = result_cls;
504 mqm = GNUNET_MQ_msg_nested_mh (msg, GNUNET_MESSAGE_TYPE_SET_EVALUATE, context_msg);
506 msg->app_id = *app_id;
507 msg->target_peer = *other_peer;
510 oh->conclude_mqm = mqm;
511 oh->request_id_addr = &msg->request_id;
517 * Wait for set operation requests for the given application id
519 * @param cfg configuration to use for connecting to
521 * @param operation operation we want to listen for
522 * @param app_id id of the application that handles set operation requests
523 * @param listen_cb called for each incoming request matching the operation
525 * @param listen_cls handle for listen_cb
526 * @return a handle that can be used to cancel the listen operation
528 struct GNUNET_SET_ListenHandle *
529 GNUNET_SET_listen (const struct GNUNET_CONFIGURATION_Handle *cfg,
530 enum GNUNET_SET_OperationType operation,
531 const struct GNUNET_HashCode *app_id,
532 GNUNET_SET_ListenCallback listen_cb,
535 struct GNUNET_SET_ListenHandle *lh;
536 struct GNUNET_MQ_Envelope *mqm;
537 struct GNUNET_SET_ListenMessage *msg;
538 static const struct GNUNET_MQ_MessageHandler mq_handlers[] = {
539 {handle_request, GNUNET_MESSAGE_TYPE_SET_REQUEST},
540 GNUNET_MQ_HANDLERS_END
543 lh = GNUNET_new (struct GNUNET_SET_ListenHandle);
544 lh->client = GNUNET_CLIENT_connect ("set", cfg);
545 lh->listen_cb = listen_cb;
546 lh->listen_cls = listen_cls;
547 GNUNET_assert (NULL != lh->client);
548 lh->mq = GNUNET_MQ_queue_for_connection_client (lh->client, mq_handlers,
549 handle_client_listener_error, lh);
550 mqm = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_SET_LISTEN);
551 msg->operation = htons (operation);
552 msg->app_id = *app_id;
553 GNUNET_MQ_send (lh->mq, mqm);
560 * Cancel the given listen operation.
562 * @param lh handle for the listen operation
565 GNUNET_SET_listen_cancel (struct GNUNET_SET_ListenHandle *lh)
567 LOG (GNUNET_ERROR_TYPE_DEBUG, "canceling listener\n");
568 GNUNET_MQ_destroy (lh->mq);
569 GNUNET_CLIENT_disconnect (lh->client);
575 * Accept a request we got via GNUNET_SET_listen. Must be called during
576 * GNUNET_SET_listen, as the 'struct GNUNET_SET_Request' becomes invalid
578 * Call GNUNET_SET_conclude to provide the local set to use for the operation,
579 * and to begin the exchange with the remote peer.
581 * @param request request to accept
582 * @param result_mode specified how results will be returned,
583 * see 'GNUNET_SET_ResultMode'.
584 * @param result_cb callback for the results
585 * @param result_cls closure for result_cb
586 * @return a handle to cancel the operation
588 struct GNUNET_SET_OperationHandle *
589 GNUNET_SET_accept (struct GNUNET_SET_Request *request,
590 enum GNUNET_SET_ResultMode result_mode,
591 GNUNET_SET_ResultIterator result_cb,
594 struct GNUNET_MQ_Envelope *mqm;
595 struct GNUNET_SET_OperationHandle *oh;
596 struct GNUNET_SET_AcceptRejectMessage *msg;
598 GNUNET_assert (NULL != request);
599 GNUNET_assert (GNUNET_NO == request->accepted);
600 request->accepted = GNUNET_YES;
602 oh = GNUNET_new (struct GNUNET_SET_OperationHandle);
603 oh->result_cb = result_cb;
604 oh->result_cls = result_cls;
606 mqm = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_SET_ACCEPT);
607 msg->accept_reject_id = htonl (request->accept_id);
609 oh->conclude_mqm = mqm;
610 oh->request_id_addr = &msg->request_id;
617 * Cancel the given set operation.
618 * We need to send an explicit cancel message, as
619 * all operations communicate with the set's client
622 * @param oh set operation to cancel
625 GNUNET_SET_operation_cancel (struct GNUNET_SET_OperationHandle *oh)
627 if (NULL != oh->conclude_mqm)
628 GNUNET_MQ_discard (oh->conclude_mqm);
630 /* is the operation already commited? */
633 struct GNUNET_SET_OperationHandle *h_assoc;
634 struct GNUNET_MQ_Envelope *mqm;
636 GNUNET_CONTAINER_DLL_remove (oh->set->ops_head, oh->set->ops_tail, oh);
637 h_assoc = GNUNET_MQ_assoc_remove (oh->set->mq, oh->request_id);
638 GNUNET_assert ((h_assoc == NULL) || (h_assoc == oh));
639 mqm = GNUNET_MQ_msg_header (GNUNET_MESSAGE_TYPE_SET_CANCEL);
640 GNUNET_MQ_send (oh->set->mq, mqm);
642 if (GNUNET_YES == oh->set->destroy_requested)
643 GNUNET_SET_destroy (oh->set);
651 * Commit a set to be used with a set operation.
652 * This function is called once we have fully constructed
653 * the set that we want to use for the operation. At this
654 * time, the P2P protocol can then begin to exchange the
655 * set information and call the result callback with the
656 * result information.
658 * @param oh handle to the set operation
659 * @param set the set to use for the operation
660 * @return GNUNET_OK on success, GNUNET_SYSERR if the
661 * set is invalid (e.g. the set service crashed)
664 GNUNET_SET_commit (struct GNUNET_SET_OperationHandle *oh,
665 struct GNUNET_SET_Handle *set)
667 GNUNET_assert (NULL == oh->set);
668 if (GNUNET_YES == set->invalid)
669 return GNUNET_SYSERR;
670 GNUNET_assert (NULL != oh->conclude_mqm);
672 GNUNET_CONTAINER_DLL_insert (set->ops_head, set->ops_tail, oh);
673 oh->request_id = GNUNET_MQ_assoc_add (set->mq, oh);
674 *oh->request_id_addr = htonl (oh->request_id);
675 GNUNET_MQ_send (set->mq, oh->conclude_mqm);
676 oh->conclude_mqm = NULL;
677 oh->request_id_addr = NULL;
684 * Iterate over all elements in the given set.
685 * Note that this operation involves transferring every element of the set
686 * from the service to the client, and is thus costly.
688 * @param set the set to iterate over
689 * @param iter the iterator to call for each element
690 * @param cls closure for 'iter'
691 * @return GNUNET_YES if the iteration started successfuly,
692 * GNUNET_NO if another iteration is active
693 * GNUNET_SYSERR if the set is invalid (e.g. the server crashed, disconnected)
696 GNUNET_SET_iterate (struct GNUNET_SET_Handle *set, GNUNET_SET_ElementIterator iter, void *cls)
698 struct GNUNET_MQ_Envelope *ev;
700 GNUNET_assert (NULL != iter);
702 if (GNUNET_YES == set->invalid)
703 return GNUNET_SYSERR;
704 if (NULL != set->iterator)
707 set->iterator = iter;
708 set->iterator_cls = cls;
709 ev = GNUNET_MQ_msg_header (GNUNET_MESSAGE_TYPE_SET_ITER_REQUEST);
710 GNUNET_MQ_send (set->mq, ev);