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1/*
2 This file is part of GNUnet.
3 Copyright (C) 2013 GNUnet e.V.
4
5 GNUnet is free software: you can redistribute it and/or modify it
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,
8 or (at your option) any later version.
9
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 Affero General Public License for more details.
14
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/>.
17
18 SPDX-License-Identifier: AGPL3.0-or-later
19*/
20
21/**
22 * @author Gabor X Toth
23 * @author Christian Grothoff
24 *
25 * @file
26 * PSYCstore service; implements persistent storage for the PSYC service
27 *
28 * @defgroup psycstore PSYC Store service
29 * Persistent storage for the PSYC service.
30 * @{
31 */
32#ifndef GNUNET_PSYCSTORE_SERVICE_H
33#define GNUNET_PSYCSTORE_SERVICE_H
34
35#ifdef __cplusplus
36extern "C"
37{
38#if 0 /* keep Emacsens' auto-indent happy */
39}
40#endif
41#endif
42
43#include "gnunet_util_lib.h"
44#include "gnunet_psyc_util_lib.h"
45#include "gnunet_multicast_service.h"
46#include "gnunet_psyc_service.h"
47
48/**
49 * Version number of GNUnet PSYCstore API.
50 */
51#define GNUNET_PSYCSTORE_VERSION 0x00000000
52
53/**
54 * Membership test failed.
55 */
56#define GNUNET_PSYCSTORE_MEMBERSHIP_TEST_FAILED -2
57
58/**
59 * Flags for stored messages.
60 */
61enum GNUNET_PSYCSTORE_MessageFlags
62{
63 /**
64 * The message contains state modifiers.
65 */
66 GNUNET_PSYCSTORE_MESSAGE_STATE = 1 << 0,
67
68 /**
69 * The state modifiers have been applied to the state store.
70 */
71 GNUNET_PSYCSTORE_MESSAGE_STATE_APPLIED = 1 << 1,
72
73 /**
74 * The message contains a state hash.
75 */
76 GNUNET_PSYCSTORE_MESSAGE_STATE_HASH = 1 << 2
77};
78
79
80/**
81 * Handle for a PSYCstore
82 */
83struct GNUNET_PSYCSTORE_Handle;
84
85
86/**
87 * Connect to the PSYCstore service.
88 *
89 * @param cfg Configuration to use.
90 *
91 * @return Handle for the connecton.
92 */
93struct GNUNET_PSYCSTORE_Handle *
94GNUNET_PSYCSTORE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg);
95
96
97/**
98 * Disconnect from the PSYCstore service.
99 *
100 * @param h Handle for the connection.
101 */
102void
103GNUNET_PSYCSTORE_disconnect (struct GNUNET_PSYCSTORE_Handle *h);
104
105
106/**
107 * Handle for an operation on the PSYCSTORE (useful to cancel the operation).
108 */
109struct GNUNET_PSYCSTORE_OperationHandle;
110
111
112/**
113 * Function called with the result of an asynchronous operation.
114 *
115 * @param cls
116 * Closure.
117 * @param result
118 * Result of the operation.
119 * @param err_msg
120 * Error message, or NULL if there's no error.
121 * @param err_msg_size
122 * Size of @a err_msg
123 */
124typedef void
125(*GNUNET_PSYCSTORE_ResultCallback) (void *cls,
126 int64_t result,
127 const char *err_msg,
128 uint16_t err_msg_size);
129
130
131/**
132 * Store join/leave events for a PSYC channel in order to be able to answer
133 * membership test queries later.
134 *
135 * @param h
136 * Handle for the PSYCstore.
137 * @param channel_key
138 * The channel where the event happened.
139 * @param slave_key
140 * Public key of joining/leaving slave.
141 * @param did_join
142 * #GNUNET_YES on join, #GNUNET_NO on part.
143 * @param announced_at
144 * ID of the message that announced the membership change.
145 * @param effective_since
146 * Message ID this membership change is in effect since.
147 * For joins it is <= announced_at, for parts it is always 0.
148 * @param group_generation
149 * In case of a part, the last group generation the slave has access to.
150 * It has relevance when a larger message have fragments with different
151 * group generations.
152 * @param result_cb
153 * Callback to call with the result of the storage operation.
154 * @param cls
155 * Closure for the callback.
156 *
157 * @return Operation handle that can be used to cancel the operation.
158 */
159struct GNUNET_PSYCSTORE_OperationHandle *
160GNUNET_PSYCSTORE_membership_store (struct GNUNET_PSYCSTORE_Handle *h,
161 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
162 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_key,
163 int did_join,
164 uint64_t announced_at,
165 uint64_t effective_since,
166 uint64_t group_generation,
167 GNUNET_PSYCSTORE_ResultCallback result_cb,
168 void *cls);
169
170
171/**
172 * Test if a member was admitted to the channel at the given message ID.
173 *
174 * This is useful when relaying and replaying messages to check if a particular
175 * slave has access to the message fragment with a given group generation. It
176 * is also used when handling join requests to determine whether the slave is
177 * currently admitted to the channel.
178 *
179 * @param h
180 * Handle for the PSYCstore.
181 * @param channel_key
182 * The channel we are interested in.
183 * @param slave_key
184 * Public key of slave whose membership to check.
185 * @param message_id
186 * Message ID for which to do the membership test.
187 * @param group_generation
188 * Group generation of the fragment of the message to test.
189 * It has relevance if the message consists of multiple fragments with
190 * different group generations.
191 * @param result_cb
192 * Callback to call with the test result.
193 * @param cls
194 * Closure for the callback.
195 *
196 * @return Operation handle that can be used to cancel the operation.
197 */
198struct GNUNET_PSYCSTORE_OperationHandle *
199GNUNET_PSYCSTORE_membership_test (struct GNUNET_PSYCSTORE_Handle *h,
200 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
201 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_key,
202 uint64_t message_id,
203 uint64_t group_generation,
204 GNUNET_PSYCSTORE_ResultCallback result_cb,
205 void *cls);
206
207
208/**
209 * Store a message fragment sent to a channel.
210 *
211 * @param h Handle for the PSYCstore.
212 * @param channel_key The channel the message belongs to.
213 * @param msg Message to store.
214 * @param psycstore_flags Flags indicating whether the PSYC message contains
215 * state modifiers.
216 * @param result_cb Callback to call with the result of the operation.
217 * @param cls Closure for the callback.
218 *
219 * @return Handle that can be used to cancel the operation.
220 */
221struct GNUNET_PSYCSTORE_OperationHandle *
222GNUNET_PSYCSTORE_fragment_store (struct GNUNET_PSYCSTORE_Handle *h,
223 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
224 const struct GNUNET_MULTICAST_MessageHeader *msg,
225 enum GNUNET_PSYCSTORE_MessageFlags psycstore_flags,
226 GNUNET_PSYCSTORE_ResultCallback result_cb,
227 void *cls);
228
229
230/**
231 * Function called with one message fragment, as the result of a
232 * GNUNET_PSYCSTORE_fragment_get() or GNUNET_PSYCSTORE_message_get() call.
233 *
234 * @param cls Closure.
235 * @param message The retrieved message fragment. A NULL value indicates that
236 * there are no more results to be returned.
237 * @param psycstore_flags Flags stored with the message.
238 *
239 * @return #GNUNET_NO to stop calling this callback with further fragments,
240 * #GNUNET_YES to continue.
241 */
242typedef int
243(*GNUNET_PSYCSTORE_FragmentCallback) (void *cls,
244 struct GNUNET_MULTICAST_MessageHeader *message,
245 enum GNUNET_PSYCSTORE_MessageFlags psycstore_flags);
246
247
248/**
249 * Retrieve message fragments by fragment ID range.
250 *
251 * @param h
252 * Handle for the PSYCstore.
253 * @param channel_key
254 * The channel we are interested in.
255 * @param slave_key
256 * The slave requesting the fragment. If not NULL, a membership test is
257 * performed first and the fragment is only returned if the slave has
258 * access to it.
259 * @param first_fragment_id
260 * First fragment ID to retrieve.
261 * Use 0 to get the latest message fragment.
262 * @param last_fragment_id
263 * Last consecutive fragment ID to retrieve.
264 * Use 0 to get the latest message fragment.
265 * @param fragment_cb
266 * Callback to call with the retrieved fragments.
267 * @param result_cb
268 * Callback to call with the result of the operation.
269 * @param cls
270 * Closure for the callbacks.
271 *
272 * @return Handle that can be used to cancel the operation.
273 */
274struct GNUNET_PSYCSTORE_OperationHandle *
275GNUNET_PSYCSTORE_fragment_get (struct GNUNET_PSYCSTORE_Handle *h,
276 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
277 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_key,
278 uint64_t first_message_id,
279 uint64_t last_message_id,
280 GNUNET_PSYCSTORE_FragmentCallback fragment_cb,
281 GNUNET_PSYCSTORE_ResultCallback result_cb,
282 void *cls);
283
284
285/**
286 * Retrieve latest message fragments.
287 *
288 * @param h
289 * Handle for the PSYCstore.
290 * @param channel_key
291 * The channel we are interested in.
292 * @param slave_key
293 * The slave requesting the fragment. If not NULL, a membership test is
294 * performed first and the fragment is only returned if the slave has
295 * access to it.
296 * @param first_fragment_id
297 * First fragment ID to retrieve.
298 * Use 0 to get the latest message fragment.
299 * @param last_fragment_id
300 * Last consecutive fragment ID to retrieve.
301 * Use 0 to get the latest message fragment.
302 * @param fragment_limit
303 * Maximum number of fragments to retrieve.
304 * @param fragment_cb
305 * Callback to call with the retrieved fragments.
306 * @param result_cb
307 * Callback to call with the result of the operation.
308 * @param cls
309 * Closure for the callbacks.
310 *
311 * @return Handle that can be used to cancel the operation.
312 */
313struct GNUNET_PSYCSTORE_OperationHandle *
314GNUNET_PSYCSTORE_fragment_get_latest (struct GNUNET_PSYCSTORE_Handle *h,
315 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
316 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_key,
317 uint64_t fragment_limit,
318 GNUNET_PSYCSTORE_FragmentCallback fragment_cb,
319 GNUNET_PSYCSTORE_ResultCallback result_cb,
320 void *cls);
321
322
323/**
324 * Retrieve all fragments of messages in a message ID range.
325 *
326 * @param h
327 * Handle for the PSYCstore.
328 * @param channel_key
329 * The channel we are interested in.
330 * @param slave_key
331 * The slave requesting the message.
332 * If not NULL, a membership test is performed first
333 * and the message is only returned if the slave has access to it.
334 * @param first_message_id
335 * First message ID to retrieve.
336 * @param last_message_id
337 * Last consecutive message ID to retrieve.
338 * @param fragment_limit
339 * Maximum number of fragments to retrieve.
340 * @param method_prefix
341 * Retrieve only messages with a matching method prefix.
342 * @param fragment_cb
343 * Callback to call with the retrieved fragments.
344 * @param result_cb
345 * Callback to call with the result of the operation.
346 * @param cls
347 * Closure for the callbacks.
348 *
349 * @return Handle that can be used to cancel the operation.
350 */
351struct GNUNET_PSYCSTORE_OperationHandle *
352GNUNET_PSYCSTORE_message_get (struct GNUNET_PSYCSTORE_Handle *h,
353 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
354 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_key,
355 uint64_t first_message_id,
356 uint64_t last_message_id,
357 uint64_t fragment_limit,
358 const char *method_prefix,
359 GNUNET_PSYCSTORE_FragmentCallback fragment_cb,
360 GNUNET_PSYCSTORE_ResultCallback result_cb,
361 void *cls);
362
363
364/**
365 * Retrieve all fragments of the latest messages.
366 *
367 * @param h
368 * Handle for the PSYCstore.
369 * @param channel_key
370 * The channel we are interested in.
371 * @param slave_key
372 * The slave requesting the message.
373 * If not NULL, a membership test is performed first
374 * and the message is only returned if the slave has access to it.
375 * @param message_limit
376 * Maximum number of messages to retrieve.
377 * @param method_prefix
378 * Retrieve only messages with a matching method prefix.
379 * @param fragment_cb
380 * Callback to call with the retrieved fragments.
381 * @param result_cb
382 * Callback to call with the result of the operation.
383 * @param cls
384 * Closure for the callbacks.
385 *
386 * @return Handle that can be used to cancel the operation.
387 */
388struct GNUNET_PSYCSTORE_OperationHandle *
389GNUNET_PSYCSTORE_message_get_latest (struct GNUNET_PSYCSTORE_Handle *h,
390 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
391 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_key,
392 uint64_t message_limit,
393 const char *method_prefix,
394 GNUNET_PSYCSTORE_FragmentCallback fragment_cb,
395 GNUNET_PSYCSTORE_ResultCallback result_cb,
396 void *cls);
397
398
399/**
400 * Retrieve a fragment of message specified by its message ID and fragment
401 * offset.
402 *
403 * @param h
404 * Handle for the PSYCstore.
405 * @param channel_key
406 * The channel we are interested in.
407 * @param slave_key
408 * The slave requesting the message fragment. If not NULL, a membership
409 * test is performed first and the message fragment is only returned
410 * if the slave has access to it.
411 * @param message_id
412 * Message ID to retrieve. Use 0 to get the latest message.
413 * @param fragment_offset
414 * Offset of the fragment to retrieve.
415 * @param fragment_cb
416 * Callback to call with the retrieved fragments.
417 * @param result_cb
418 * Callback to call with the result of the operation.
419 * @param cls
420 * Closure for the callbacks.
421 *
422 * @return Handle that can be used to cancel the operation.
423 */
424struct GNUNET_PSYCSTORE_OperationHandle *
425GNUNET_PSYCSTORE_message_get_fragment (struct GNUNET_PSYCSTORE_Handle *h,
426 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
427 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_key,
428 uint64_t message_id,
429 uint64_t fragment_offset,
430 GNUNET_PSYCSTORE_FragmentCallback fragment_cb,
431 GNUNET_PSYCSTORE_ResultCallback result_cb,
432 void *cls);
433
434
435/**
436 * Callback used to return the latest value of counters for the channel master.
437 *
438 * @see GNUNET_PSYCSTORE_counters_get()
439 *
440 * @param cls Closure.
441 * @param result_code
442 * Status code for the operation:
443 * #GNUNET_OK: success, counter values are returned.
444 * #GNUNET_NO: no message has been sent to the channel yet.
445 * #GNUNET_SYSERR: an error occurred.
446 * @param max_fragment_id
447 * Latest message fragment ID, used by multicast.
448 * @param max_message_id
449 * Latest message ID, used by PSYC.
450 * @param max_group_generation
451 * Latest group generation, used by PSYC.
452 * @param max_state_message_id
453 * Latest message ID containing state modifiers that
454 * was applied to the state store. Used for the state sync process.
455 */
456typedef void
457(*GNUNET_PSYCSTORE_CountersCallback) (void *cls,
458 int result_code,
459 uint64_t max_fragment_id,
460 uint64_t max_message_id,
461 uint64_t max_group_generation,
462 uint64_t max_state_message_id);
463
464
465/**
466 * Retrieve latest values of counters for a channel.
467 *
468 * The current value of counters are needed
469 * - when a channel master is restarted, so that it can continue incrementing
470 * the counters from their last value.
471 * - when a channel slave rejoins and starts the state synchronization process.
472 *
473 * @param h
474 * Handle for the PSYCstore.
475 * @param channel_key
476 * Public key that identifies the channel.
477 * @param counters_cb
478 * Callback to call with the result.
479 * @param cls
480 * Closure for the @a ccb callback.
481 *
482 * @return Handle that can be used to cancel the operation.
483 */
484struct GNUNET_PSYCSTORE_OperationHandle *
485GNUNET_PSYCSTORE_counters_get (struct GNUNET_PSYCSTORE_Handle *h,
486 struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
487 GNUNET_PSYCSTORE_CountersCallback counters_cb,
488 void *cls);
489
490
491/**
492 * Apply modifiers of a message to the current channel state.
493 *
494 * An error is returned if there are missing messages containing state
495 * operations before the current one.
496 *
497 * @param h
498 * Handle for the PSYCstore.
499 * @param channel_key
500 * The channel we are interested in.
501 * @param message_id
502 * ID of the message that contains the @a modifiers.
503 * @param state_delta
504 * Value of the @e state_delta PSYC header variable of the message.
505 * @param result_cb
506 * Callback to call with the result of the operation.
507 * @param cls
508 * Closure for the @a result_cb callback.
509 *
510 * @return Handle that can be used to cancel the operation.
511 */
512struct GNUNET_PSYCSTORE_OperationHandle *
513GNUNET_PSYCSTORE_state_modify (struct GNUNET_PSYCSTORE_Handle *h,
514 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
515 uint64_t message_id,
516 uint64_t state_delta,
517 GNUNET_PSYCSTORE_ResultCallback result_cb,
518 void *cls);
519
520
521/**
522 * Store synchronized state.
523 *
524 * @param h
525 * Handle for the PSYCstore.
526 * @param channel_key
527 * The channel we are interested in.
528 * @param max_state_message_id
529 * ID of the last stateful message before @a state_hash_message_id.
530 * @param state_hash_message_id
531 * ID of the message that contains the state_hash PSYC header variable.
532 * @param modifier_count
533 * Number of elements in the @a modifiers array.
534 * @param modifiers
535 * Full state to store.
536 * @param result_cb
537 * Callback to call with the result of the operation.
538 * @param cls
539 * Closure for the callback.
540 *
541 * @return Handle that can be used to cancel the operation.
542 */
543struct GNUNET_PSYCSTORE_OperationHandle *
544GNUNET_PSYCSTORE_state_sync (struct GNUNET_PSYCSTORE_Handle *h,
545 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
546 uint64_t max_state_message_id,
547 uint64_t state_hash_message_id,
548 size_t modifier_count,
549 const struct GNUNET_PSYC_Modifier *modifiers,
550 GNUNET_PSYCSTORE_ResultCallback result_cb,
551 void *cls);
552
553
554
555/**
556 * Reset the state of a channel.
557 *
558 * Delete all state variables stored for the given channel.
559 *
560 * @param h
561 * Handle for the PSYCstore.
562 * @param channel_key
563 * The channel we are interested in.
564 * @param result_cb
565 * Callback to call with the result of the operation.
566 * @param cls
567 * Closure for the callback.
568 *
569 * @return Handle that can be used to cancel the operation.
570 */
571struct GNUNET_PSYCSTORE_OperationHandle *
572GNUNET_PSYCSTORE_state_reset (struct GNUNET_PSYCSTORE_Handle *h,
573 const struct GNUNET_CRYPTO_EddsaPublicKey
574 *channel_key,
575 GNUNET_PSYCSTORE_ResultCallback result_cb,
576 void *cls);
577
578
579/**
580 * Update signed values of state variables in the state store.
581 *
582 * @param h
583 * Handle for the PSYCstore.
584 * @param channel_key
585 * The channel we are interested in.
586 * @param message_id
587 * Message ID that contained the state @a hash.
588 * @param hash
589 * Hash of the serialized full state.
590 * @param result_cb
591 * Callback to call with the result of the operation.
592 * @param cls
593 * Closure for the callback.
594 *
595 */
596struct GNUNET_PSYCSTORE_OperationHandle *
597GNUNET_PSYCSTORE_state_hash_update (struct GNUNET_PSYCSTORE_Handle *h,
598 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
599 uint64_t message_id,
600 const struct GNUNET_HashCode *hash,
601 GNUNET_PSYCSTORE_ResultCallback result_cb,
602 void *cls);
603
604
605/**
606 * Function called with the value of a state variable.
607 *
608 * @param cls
609 * Closure.
610 * @param name
611 * Name of the state variable. A NULL value indicates that there are no more
612 * state variables to be returned.
613 * @param value
614 * Value of the state variable.
615 * @param value_size
616 * Number of bytes in @a value.
617 *
618 * @return #GNUNET_NO to stop calling this callback with further variables,
619 * #GNUNET_YES to continue.
620 */;
621typedef int
622(*GNUNET_PSYCSTORE_StateCallback) (void *cls, const char *name,
623 const void *value, uint32_t value_size);
624
625
626/**
627 * Retrieve the best matching state variable.
628 *
629 * @param h
630 * Handle for the PSYCstore.
631 * @param channel_key
632 * The channel we are interested in.
633 * @param name
634 * Name of variable to match, the returned variable might be less specific.
635 * @param state_cb
636 * Callback to return the matching state variable.
637 * @param result_cb
638 * Callback to call with the result of the operation.
639 * @param cls
640 * Closure for the callbacks.
641 *
642 * @return Handle that can be used to cancel the operation.
643 */
644struct GNUNET_PSYCSTORE_OperationHandle *
645GNUNET_PSYCSTORE_state_get (struct GNUNET_PSYCSTORE_Handle *h,
646 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
647 const char *name,
648 GNUNET_PSYCSTORE_StateCallback state_cb,
649 GNUNET_PSYCSTORE_ResultCallback result_cb,
650 void *cls);
651
652
653/**
654 * Retrieve all state variables for a channel with the given prefix.
655 *
656 * @param h
657 * Handle for the PSYCstore.
658 * @param channel_key
659 * The channel we are interested in.
660 * @param name_prefix
661 * Prefix of state variable names to match.
662 * @param state_cb
663 * Callback to return matching state variables.
664 * @param result_cb
665 * Callback to call with the result of the operation.
666 * @param cls
667 * Closure for the callbacks.
668 *
669 * @return Handle that can be used to cancel the operation.
670 */
671struct GNUNET_PSYCSTORE_OperationHandle *
672GNUNET_PSYCSTORE_state_get_prefix (struct GNUNET_PSYCSTORE_Handle *h,
673 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
674 const char *name_prefix,
675 GNUNET_PSYCSTORE_StateCallback state_cb,
676 GNUNET_PSYCSTORE_ResultCallback result_cb,
677 void *cls);
678
679
680/**
681 * Cancel an operation.
682 *
683 * @param op Handle for the operation to cancel.
684 */
685int
686GNUNET_PSYCSTORE_operation_cancel (struct GNUNET_PSYCSTORE_OperationHandle *op);
687
688
689
690
691#if 0 /* keep Emacsens' auto-indent happy */
692{
693#endif
694#ifdef __cplusplus
695}
696#endif
697
698/* ifndef GNUNET_PSYCSTORE_SERVICE_H */
699#endif
700
701/** @} */ /* end of group */