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diff --git a/src/set/gnunet-service-set_intersection.c b/src/set/gnunet-service-set_intersection.c
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1/*
2 This file is part of GNUnet
3 Copyright (C) 2013-2017 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 * @file set/gnunet-service-set_intersection.c
22 * @brief two-peer set intersection
23 * @author Christian Fuchs
24 * @author Christian Grothoff
25 */
26#include "platform.h"
27#include "gnunet_util_lib.h"
28#include "gnunet_statistics_service.h"
29#include "gnunet-service-set.h"
30#include "gnunet_block_lib.h"
31#include "gnunet-service-set_protocol.h"
32#include "gnunet-service-set_intersection.h"
33#include <gcrypt.h>
34
35
36/**
37 * Current phase we are in for a intersection operation.
38 */
39enum IntersectionOperationPhase
40{
41 /**
42 * We are just starting.
43 */
44 PHASE_INITIAL,
45
46 /**
47 * We have send the number of our elements to the other
48 * peer, but did not setup our element set yet.
49 */
50 PHASE_COUNT_SENT,
51
52 /**
53 * We have initialized our set and are now reducing it by exchanging
54 * Bloom filters until one party notices the their element hashes
55 * are equal.
56 */
57 PHASE_BF_EXCHANGE,
58
59 /**
60 * We must next send the P2P DONE message (after finishing mostly
61 * with the local client). Then we will wait for the channel to close.
62 */
63 PHASE_MUST_SEND_DONE,
64
65 /**
66 * We have received the P2P DONE message, and must finish with the
67 * local client before terminating the channel.
68 */
69 PHASE_DONE_RECEIVED,
70
71 /**
72 * The protocol is over. Results may still have to be sent to the
73 * client.
74 */
75 PHASE_FINISHED
76};
77
78
79/**
80 * State of an evaluate operation with another peer.
81 */
82struct OperationState
83{
84 /**
85 * The bf we currently receive
86 */
87 struct GNUNET_CONTAINER_BloomFilter *remote_bf;
88
89 /**
90 * BF of the set's element.
91 */
92 struct GNUNET_CONTAINER_BloomFilter *local_bf;
93
94 /**
95 * Remaining elements in the intersection operation.
96 * Maps element-id-hashes to 'elements in our set'.
97 */
98 struct GNUNET_CONTAINER_MultiHashMap *my_elements;
99
100 /**
101 * Iterator for sending the final set of @e my_elements to the client.
102 */
103 struct GNUNET_CONTAINER_MultiHashMapIterator *full_result_iter;
104
105 /**
106 * Evaluate operations are held in a linked list.
107 */
108 struct OperationState *next;
109
110 /**
111 * Evaluate operations are held in a linked list.
112 */
113 struct OperationState *prev;
114
115 /**
116 * For multipart BF transmissions, we have to store the
117 * bloomfilter-data until we fully received it.
118 */
119 char *bf_data;
120
121 /**
122 * XOR of the keys of all of the elements (remaining) in my set.
123 * Always updated when elements are added or removed to
124 * @e my_elements.
125 */
126 struct GNUNET_HashCode my_xor;
127
128 /**
129 * XOR of the keys of all of the elements (remaining) in
130 * the other peer's set. Updated when we receive the
131 * other peer's Bloom filter.
132 */
133 struct GNUNET_HashCode other_xor;
134
135 /**
136 * How many bytes of @e bf_data are valid?
137 */
138 uint32_t bf_data_offset;
139
140 /**
141 * Current element count contained within @e my_elements.
142 * (May differ briefly during initialization.)
143 */
144 uint32_t my_element_count;
145
146 /**
147 * size of the bloomfilter in @e bf_data.
148 */
149 uint32_t bf_data_size;
150
151 /**
152 * size of the bloomfilter
153 */
154 uint32_t bf_bits_per_element;
155
156 /**
157 * Salt currently used for BF construction (by us or the other peer,
158 * depending on where we are in the code).
159 */
160 uint32_t salt;
161
162 /**
163 * Current state of the operation.
164 */
165 enum IntersectionOperationPhase phase;
166
167 /**
168 * Generation in which the operation handle
169 * was created.
170 */
171 unsigned int generation_created;
172
173 /**
174 * Did we send the client that we are done?
175 */
176 int client_done_sent;
177
178 /**
179 * Set whenever we reach the state where the death of the
180 * channel is perfectly find and should NOT result in the
181 * operation being cancelled.
182 */
183 int channel_death_expected;
184};
185
186
187/**
188 * Extra state required for efficient set intersection.
189 * Merely tracks the total number of elements.
190 */
191struct SetState
192{
193 /**
194 * Number of currently valid elements in the set which have not been
195 * removed.
196 */
197 uint32_t current_set_element_count;
198};
199
200
201/**
202 * If applicable in the current operation mode, send a result message
203 * to the client indicating we removed an element.
204 *
205 * @param op intersection operation
206 * @param element element to send
207 */
208static void
209send_client_removed_element (struct Operation *op,
210 struct GNUNET_SET_Element *element)
211{
212 struct GNUNET_MQ_Envelope *ev;
213 struct GNUNET_SET_ResultMessage *rm;
214
215 if (GNUNET_SET_RESULT_REMOVED != op->result_mode)
216 return; /* Wrong mode for transmitting removed elements */
217 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
218 "Sending removed element (size %u) to client\n",
219 element->size);
220 GNUNET_STATISTICS_update (_GSS_statistics,
221 "# Element removed messages sent",
222 1,
223 GNUNET_NO);
224 GNUNET_assert (0 != op->client_request_id);
225 ev = GNUNET_MQ_msg_extra (rm,
226 element->size,
227 GNUNET_MESSAGE_TYPE_SET_RESULT);
228 if (NULL == ev)
229 {
230 GNUNET_break (0);
231 return;
232 }
233 rm->result_status = htons (GNUNET_SET_STATUS_OK);
234 rm->request_id = htonl (op->client_request_id);
235 rm->element_type = element->element_type;
236 GNUNET_memcpy (&rm[1],
237 element->data,
238 element->size);
239 GNUNET_MQ_send (op->set->cs->mq,
240 ev);
241}
242
243
244/**
245 * Fills the "my_elements" hashmap with all relevant elements.
246 *
247 * @param cls the `struct Operation *` we are performing
248 * @param key current key code
249 * @param value the `struct ElementEntry *` from the hash map
250 * @return #GNUNET_YES (we should continue to iterate)
251 */
252static int
253filtered_map_initialization (void *cls,
254 const struct GNUNET_HashCode *key,
255 void *value)
256{
257 struct Operation *op = cls;
258 struct ElementEntry *ee = value;
259 struct GNUNET_HashCode mutated_hash;
260
261
262 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
263 "FIMA called for %s:%u\n",
264 GNUNET_h2s (&ee->element_hash),
265 ee->element.size);
266
267 if (GNUNET_NO == _GSS_is_element_of_operation (ee, op))
268 {
269 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
270 "Reduced initialization, not starting with %s:%u (wrong generation)\n",
271 GNUNET_h2s (&ee->element_hash),
272 ee->element.size);
273 return GNUNET_YES; /* element not valid in our operation's generation */
274 }
275
276 /* Test if element is in other peer's bloomfilter */
277 GNUNET_BLOCK_mingle_hash (&ee->element_hash,
278 op->state->salt,
279 &mutated_hash);
280 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
281 "Testing mingled hash %s with salt %u\n",
282 GNUNET_h2s (&mutated_hash),
283 op->state->salt);
284 if (GNUNET_NO ==
285 GNUNET_CONTAINER_bloomfilter_test (op->state->remote_bf,
286 &mutated_hash))
287 {
288 /* remove this element */
289 send_client_removed_element (op,
290 &ee->element);
291 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
292 "Reduced initialization, not starting with %s:%u\n",
293 GNUNET_h2s (&ee->element_hash),
294 ee->element.size);
295 return GNUNET_YES;
296 }
297 op->state->my_element_count++;
298 GNUNET_CRYPTO_hash_xor (&op->state->my_xor,
299 &ee->element_hash,
300 &op->state->my_xor);
301 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
302 "Filtered initialization of my_elements, adding %s:%u\n",
303 GNUNET_h2s (&ee->element_hash),
304 ee->element.size);
305 GNUNET_break (GNUNET_YES ==
306 GNUNET_CONTAINER_multihashmap_put (op->state->my_elements,
307 &ee->element_hash,
308 ee,
309 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
310
311 return GNUNET_YES;
312}
313
314
315/**
316 * Removes elements from our hashmap if they are not contained within the
317 * provided remote bloomfilter.
318 *
319 * @param cls closure with the `struct Operation *`
320 * @param key current key code
321 * @param value value in the hash map
322 * @return #GNUNET_YES (we should continue to iterate)
323 */
324static int
325iterator_bf_reduce (void *cls,
326 const struct GNUNET_HashCode *key,
327 void *value)
328{
329 struct Operation *op = cls;
330 struct ElementEntry *ee = value;
331 struct GNUNET_HashCode mutated_hash;
332
333 GNUNET_BLOCK_mingle_hash (&ee->element_hash,
334 op->state->salt,
335 &mutated_hash);
336 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
337 "Testing mingled hash %s with salt %u\n",
338 GNUNET_h2s (&mutated_hash),
339 op->state->salt);
340 if (GNUNET_NO ==
341 GNUNET_CONTAINER_bloomfilter_test (op->state->remote_bf,
342 &mutated_hash))
343 {
344 GNUNET_break (0 < op->state->my_element_count);
345 op->state->my_element_count--;
346 GNUNET_CRYPTO_hash_xor (&op->state->my_xor,
347 &ee->element_hash,
348 &op->state->my_xor);
349 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
350 "Bloom filter reduction of my_elements, removing %s:%u\n",
351 GNUNET_h2s (&ee->element_hash),
352 ee->element.size);
353 GNUNET_assert (GNUNET_YES ==
354 GNUNET_CONTAINER_multihashmap_remove (op->state->my_elements,
355 &ee->element_hash,
356 ee));
357 send_client_removed_element (op,
358 &ee->element);
359 }
360 else
361 {
362 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
363 "Bloom filter reduction of my_elements, keeping %s:%u\n",
364 GNUNET_h2s (&ee->element_hash),
365 ee->element.size);
366 }
367 return GNUNET_YES;
368}
369
370
371/**
372 * Create initial bloomfilter based on all the elements given.
373 *
374 * @param cls the `struct Operation *`
375 * @param key current key code
376 * @param value the `struct ElementEntry` to process
377 * @return #GNUNET_YES (we should continue to iterate)
378 */
379static int
380iterator_bf_create (void *cls,
381 const struct GNUNET_HashCode *key,
382 void *value)
383{
384 struct Operation *op = cls;
385 struct ElementEntry *ee = value;
386 struct GNUNET_HashCode mutated_hash;
387
388 GNUNET_BLOCK_mingle_hash (&ee->element_hash,
389 op->state->salt,
390 &mutated_hash);
391 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
392 "Initializing BF with hash %s with salt %u\n",
393 GNUNET_h2s (&mutated_hash),
394 op->state->salt);
395 GNUNET_CONTAINER_bloomfilter_add (op->state->local_bf,
396 &mutated_hash);
397 return GNUNET_YES;
398}
399
400
401/**
402 * Inform the client that the intersection operation has failed,
403 * and proceed to destroy the evaluate operation.
404 *
405 * @param op the intersection operation to fail
406 */
407static void
408fail_intersection_operation (struct Operation *op)
409{
410 struct GNUNET_MQ_Envelope *ev;
411 struct GNUNET_SET_ResultMessage *msg;
412
413 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
414 "Intersection operation failed\n");
415 GNUNET_STATISTICS_update (_GSS_statistics,
416 "# Intersection operations failed",
417 1,
418 GNUNET_NO);
419 if (NULL != op->state->my_elements)
420 {
421 GNUNET_CONTAINER_multihashmap_destroy (op->state->my_elements);
422 op->state->my_elements = NULL;
423 }
424 ev = GNUNET_MQ_msg (msg,
425 GNUNET_MESSAGE_TYPE_SET_RESULT);
426 msg->result_status = htons (GNUNET_SET_STATUS_FAILURE);
427 msg->request_id = htonl (op->client_request_id);
428 msg->element_type = htons (0);
429 GNUNET_MQ_send (op->set->cs->mq,
430 ev);
431 _GSS_operation_destroy (op,
432 GNUNET_YES);
433}
434
435
436/**
437 * Send a bloomfilter to our peer. After the result done message has
438 * been sent to the client, destroy the evaluate operation.
439 *
440 * @param op intersection operation
441 */
442static void
443send_bloomfilter (struct Operation *op)
444{
445 struct GNUNET_MQ_Envelope *ev;
446 struct BFMessage *msg;
447 uint32_t bf_size;
448 uint32_t bf_elementbits;
449 uint32_t chunk_size;
450 char *bf_data;
451 uint32_t offset;
452
453 /* We consider the ratio of the set sizes to determine
454 the number of bits per element, as the smaller set
455 should use more bits to maximize its set reduction
456 potential and minimize overall bandwidth consumption. */
457 bf_elementbits = 2 + ceil (log2 ((double)
458 (op->remote_element_count
459 / (double) op->state->my_element_count)));
460 if (bf_elementbits < 1)
461 bf_elementbits = 1; /* make sure k is not 0 */
462 /* optimize BF-size to ~50% of bits set */
463 bf_size = ceil ((double) (op->state->my_element_count
464 * bf_elementbits / log (2)));
465 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
466 "Sending Bloom filter (%u) of size %u bytes\n",
467 (unsigned int) bf_elementbits,
468 (unsigned int) bf_size);
469 op->state->local_bf = GNUNET_CONTAINER_bloomfilter_init (NULL,
470 bf_size,
471 bf_elementbits);
472 op->state->salt = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
473 UINT32_MAX);
474 GNUNET_CONTAINER_multihashmap_iterate (op->state->my_elements,
475 &iterator_bf_create,
476 op);
477
478 /* send our Bloom filter */
479 GNUNET_STATISTICS_update (_GSS_statistics,
480 "# Intersection Bloom filters sent",
481 1,
482 GNUNET_NO);
483 chunk_size = 60 * 1024 - sizeof(struct BFMessage);
484 if (bf_size <= chunk_size)
485 {
486 /* singlepart */
487 chunk_size = bf_size;
488 ev = GNUNET_MQ_msg_extra (msg,
489 chunk_size,
490 GNUNET_MESSAGE_TYPE_SET_INTERSECTION_P2P_BF);
491 GNUNET_assert (GNUNET_SYSERR !=
492 GNUNET_CONTAINER_bloomfilter_get_raw_data (
493 op->state->local_bf,
494 (char *) &msg[1],
495 bf_size));
496 msg->sender_element_count = htonl (op->state->my_element_count);
497 msg->bloomfilter_total_length = htonl (bf_size);
498 msg->bits_per_element = htonl (bf_elementbits);
499 msg->sender_mutator = htonl (op->state->salt);
500 msg->element_xor_hash = op->state->my_xor;
501 GNUNET_MQ_send (op->mq, ev);
502 }
503 else
504 {
505 /* multipart */
506 bf_data = GNUNET_malloc (bf_size);
507 GNUNET_assert (GNUNET_SYSERR !=
508 GNUNET_CONTAINER_bloomfilter_get_raw_data (
509 op->state->local_bf,
510 bf_data,
511 bf_size));
512 offset = 0;
513 while (offset < bf_size)
514 {
515 if (bf_size - chunk_size < offset)
516 chunk_size = bf_size - offset;
517 ev = GNUNET_MQ_msg_extra (msg,
518 chunk_size,
519 GNUNET_MESSAGE_TYPE_SET_INTERSECTION_P2P_BF);
520 GNUNET_memcpy (&msg[1],
521 &bf_data[offset],
522 chunk_size);
523 offset += chunk_size;
524 msg->sender_element_count = htonl (op->state->my_element_count);
525 msg->bloomfilter_total_length = htonl (bf_size);
526 msg->bits_per_element = htonl (bf_elementbits);
527 msg->sender_mutator = htonl (op->state->salt);
528 msg->element_xor_hash = op->state->my_xor;
529 GNUNET_MQ_send (op->mq, ev);
530 }
531 GNUNET_free (bf_data);
532 }
533 GNUNET_CONTAINER_bloomfilter_free (op->state->local_bf);
534 op->state->local_bf = NULL;
535}
536
537
538/**
539 * Signal to the client that the operation has finished and
540 * destroy the operation.
541 *
542 * @param cls operation to destroy
543 */
544static void
545send_client_done_and_destroy (void *cls)
546{
547 struct Operation *op = cls;
548 struct GNUNET_MQ_Envelope *ev;
549 struct GNUNET_SET_ResultMessage *rm;
550
551 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
552 "Intersection succeeded, sending DONE to local client\n");
553 GNUNET_STATISTICS_update (_GSS_statistics,
554 "# Intersection operations succeeded",
555 1,
556 GNUNET_NO);
557 ev = GNUNET_MQ_msg (rm,
558 GNUNET_MESSAGE_TYPE_SET_RESULT);
559 rm->request_id = htonl (op->client_request_id);
560 rm->result_status = htons (GNUNET_SET_STATUS_DONE);
561 rm->element_type = htons (0);
562 GNUNET_MQ_send (op->set->cs->mq,
563 ev);
564 _GSS_operation_destroy (op,
565 GNUNET_YES);
566}
567
568
569/**
570 * Remember that we are done dealing with the local client
571 * AND have sent the other peer our message that we are done,
572 * so we are not just waiting for the channel to die before
573 * telling the local client that we are done as our last act.
574 *
575 * @param cls the `struct Operation`.
576 */
577static void
578finished_local_operations (void *cls)
579{
580 struct Operation *op = cls;
581
582 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
583 "DONE sent to other peer, now waiting for other end to close the channel\n");
584 op->state->phase = PHASE_FINISHED;
585 op->state->channel_death_expected = GNUNET_YES;
586}
587
588
589/**
590 * Notify the other peer that we are done. Once this message
591 * is out, we still need to notify the local client that we
592 * are done.
593 *
594 * @param op operation to notify for.
595 */
596static void
597send_p2p_done (struct Operation *op)
598{
599 struct GNUNET_MQ_Envelope *ev;
600 struct IntersectionDoneMessage *idm;
601
602 GNUNET_assert (PHASE_MUST_SEND_DONE == op->state->phase);
603 GNUNET_assert (GNUNET_NO == op->state->channel_death_expected);
604 ev = GNUNET_MQ_msg (idm,
605 GNUNET_MESSAGE_TYPE_SET_INTERSECTION_P2P_DONE);
606 idm->final_element_count = htonl (op->state->my_element_count);
607 idm->element_xor_hash = op->state->my_xor;
608 GNUNET_MQ_notify_sent (ev,
609 &finished_local_operations,
610 op);
611 GNUNET_MQ_send (op->mq,
612 ev);
613}
614
615
616/**
617 * Send all elements in the full result iterator.
618 *
619 * @param cls the `struct Operation *`
620 */
621static void
622send_remaining_elements (void *cls)
623{
624 struct Operation *op = cls;
625 const void *nxt;
626 const struct ElementEntry *ee;
627 struct GNUNET_MQ_Envelope *ev;
628 struct GNUNET_SET_ResultMessage *rm;
629 const struct GNUNET_SET_Element *element;
630 int res;
631
632 res = GNUNET_CONTAINER_multihashmap_iterator_next (
633 op->state->full_result_iter,
634 NULL,
635 &nxt);
636 if (GNUNET_NO == res)
637 {
638 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
639 "Sending done and destroy because iterator ran out\n");
640 GNUNET_CONTAINER_multihashmap_iterator_destroy (
641 op->state->full_result_iter);
642 op->state->full_result_iter = NULL;
643 if (PHASE_DONE_RECEIVED == op->state->phase)
644 {
645 op->state->phase = PHASE_FINISHED;
646 send_client_done_and_destroy (op);
647 }
648 else if (PHASE_MUST_SEND_DONE == op->state->phase)
649 {
650 send_p2p_done (op);
651 }
652 else
653 {
654 GNUNET_assert (0);
655 }
656 return;
657 }
658 ee = nxt;
659 element = &ee->element;
660 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
661 "Sending element %s:%u to client (full set)\n",
662 GNUNET_h2s (&ee->element_hash),
663 element->size);
664 GNUNET_assert (0 != op->client_request_id);
665 ev = GNUNET_MQ_msg_extra (rm,
666 element->size,
667 GNUNET_MESSAGE_TYPE_SET_RESULT);
668 GNUNET_assert (NULL != ev);
669 rm->result_status = htons (GNUNET_SET_STATUS_OK);
670 rm->request_id = htonl (op->client_request_id);
671 rm->element_type = element->element_type;
672 GNUNET_memcpy (&rm[1],
673 element->data,
674 element->size);
675 GNUNET_MQ_notify_sent (ev,
676 &send_remaining_elements,
677 op);
678 GNUNET_MQ_send (op->set->cs->mq,
679 ev);
680}
681
682
683/**
684 * Fills the "my_elements" hashmap with the initial set of
685 * (non-deleted) elements from the set of the specification.
686 *
687 * @param cls closure with the `struct Operation *`
688 * @param key current key code for the element
689 * @param value value in the hash map with the `struct ElementEntry *`
690 * @return #GNUNET_YES (we should continue to iterate)
691 */
692static int
693initialize_map_unfiltered (void *cls,
694 const struct GNUNET_HashCode *key,
695 void *value)
696{
697 struct ElementEntry *ee = value;
698 struct Operation *op = cls;
699
700 if (GNUNET_NO == _GSS_is_element_of_operation (ee, op))
701 return GNUNET_YES; /* element not live in operation's generation */
702 GNUNET_CRYPTO_hash_xor (&op->state->my_xor,
703 &ee->element_hash,
704 &op->state->my_xor);
705 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
706 "Initial full initialization of my_elements, adding %s:%u\n",
707 GNUNET_h2s (&ee->element_hash),
708 ee->element.size);
709 GNUNET_break (GNUNET_YES ==
710 GNUNET_CONTAINER_multihashmap_put (op->state->my_elements,
711 &ee->element_hash,
712 ee,
713 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
714 return GNUNET_YES;
715}
716
717
718/**
719 * Send our element count to the peer, in case our element count is
720 * lower than theirs.
721 *
722 * @param op intersection operation
723 */
724static void
725send_element_count (struct Operation *op)
726{
727 struct GNUNET_MQ_Envelope *ev;
728 struct IntersectionElementInfoMessage *msg;
729
730 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
731 "Sending our element count (%u)\n",
732 op->state->my_element_count);
733 ev = GNUNET_MQ_msg (msg,
734 GNUNET_MESSAGE_TYPE_SET_INTERSECTION_P2P_ELEMENT_INFO);
735 msg->sender_element_count = htonl (op->state->my_element_count);
736 GNUNET_MQ_send (op->mq, ev);
737}
738
739
740/**
741 * We go first, initialize our map with all elements and
742 * send the first Bloom filter.
743 *
744 * @param op operation to start exchange for
745 */
746static void
747begin_bf_exchange (struct Operation *op)
748{
749 op->state->phase = PHASE_BF_EXCHANGE;
750 GNUNET_CONTAINER_multihashmap_iterate (op->set->content->elements,
751 &initialize_map_unfiltered,
752 op);
753 send_bloomfilter (op);
754}
755
756
757/**
758 * Handle the initial `struct IntersectionElementInfoMessage` from a
759 * remote peer.
760 *
761 * @param cls the intersection operation
762 * @param mh the header of the message
763 */
764void
765handle_intersection_p2p_element_info (void *cls,
766 const struct
767 IntersectionElementInfoMessage *msg)
768{
769 struct Operation *op = cls;
770
771 if (GNUNET_SET_OPERATION_INTERSECTION != op->set->operation)
772 {
773 GNUNET_break_op (0);
774 fail_intersection_operation (op);
775 return;
776 }
777 op->remote_element_count = ntohl (msg->sender_element_count);
778 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
779 "Received remote element count (%u), I have %u\n",
780 op->remote_element_count,
781 op->state->my_element_count);
782 if (((PHASE_INITIAL != op->state->phase) &&
783 (PHASE_COUNT_SENT != op->state->phase)) ||
784 (op->state->my_element_count > op->remote_element_count) ||
785 (0 == op->state->my_element_count) ||
786 (0 == op->remote_element_count))
787 {
788 GNUNET_break_op (0);
789 fail_intersection_operation (op);
790 return;
791 }
792 GNUNET_break (NULL == op->state->remote_bf);
793 begin_bf_exchange (op);
794 GNUNET_CADET_receive_done (op->channel);
795}
796
797
798/**
799 * Process a Bloomfilter once we got all the chunks.
800 *
801 * @param op the intersection operation
802 */
803static void
804process_bf (struct Operation *op)
805{
806 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
807 "Received BF in phase %u, foreign count is %u, my element count is %u/%u\n",
808 op->state->phase,
809 op->remote_element_count,
810 op->state->my_element_count,
811 GNUNET_CONTAINER_multihashmap_size (op->set->content->elements));
812 switch (op->state->phase)
813 {
814 case PHASE_INITIAL:
815 GNUNET_break_op (0);
816 fail_intersection_operation (op);
817 return;
818
819 case PHASE_COUNT_SENT:
820 /* This is the first BF being sent, build our initial map with
821 filtering in place */
822 op->state->my_element_count = 0;
823 GNUNET_CONTAINER_multihashmap_iterate (op->set->content->elements,
824 &filtered_map_initialization,
825 op);
826 break;
827
828 case PHASE_BF_EXCHANGE:
829 /* Update our set by reduction */
830 GNUNET_CONTAINER_multihashmap_iterate (op->state->my_elements,
831 &iterator_bf_reduce,
832 op);
833 break;
834
835 case PHASE_MUST_SEND_DONE:
836 GNUNET_break_op (0);
837 fail_intersection_operation (op);
838 return;
839
840 case PHASE_DONE_RECEIVED:
841 GNUNET_break_op (0);
842 fail_intersection_operation (op);
843 return;
844
845 case PHASE_FINISHED:
846 GNUNET_break_op (0);
847 fail_intersection_operation (op);
848 return;
849 }
850 GNUNET_CONTAINER_bloomfilter_free (op->state->remote_bf);
851 op->state->remote_bf = NULL;
852
853 if ((0 == op->state->my_element_count) || /* fully disjoint */
854 ((op->state->my_element_count == op->remote_element_count) &&
855 (0 == GNUNET_memcmp (&op->state->my_xor,
856 &op->state->other_xor))))
857 {
858 /* we are done */
859 op->state->phase = PHASE_MUST_SEND_DONE;
860 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
861 "Intersection succeeded, sending DONE to other peer\n");
862 GNUNET_CONTAINER_bloomfilter_free (op->state->local_bf);
863 op->state->local_bf = NULL;
864 if (GNUNET_SET_RESULT_FULL == op->result_mode)
865 {
866 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
867 "Sending full result set (%u elements)\n",
868 GNUNET_CONTAINER_multihashmap_size (op->state->my_elements));
869 op->state->full_result_iter
870 = GNUNET_CONTAINER_multihashmap_iterator_create (
871 op->state->my_elements);
872 send_remaining_elements (op);
873 return;
874 }
875 send_p2p_done (op);
876 return;
877 }
878 op->state->phase = PHASE_BF_EXCHANGE;
879 send_bloomfilter (op);
880}
881
882
883/**
884 * Check an BF message from a remote peer.
885 *
886 * @param cls the intersection operation
887 * @param msg the header of the message
888 * @return #GNUNET_OK if @a msg is well-formed
889 */
890int
891check_intersection_p2p_bf (void *cls,
892 const struct BFMessage *msg)
893{
894 struct Operation *op = cls;
895
896 if (GNUNET_SET_OPERATION_INTERSECTION != op->set->operation)
897 {
898 GNUNET_break_op (0);
899 return GNUNET_SYSERR;
900 }
901 return GNUNET_OK;
902}
903
904
905/**
906 * Handle an BF message from a remote peer.
907 *
908 * @param cls the intersection operation
909 * @param msg the header of the message
910 */
911void
912handle_intersection_p2p_bf (void *cls,
913 const struct BFMessage *msg)
914{
915 struct Operation *op = cls;
916 uint32_t bf_size;
917 uint32_t chunk_size;
918 uint32_t bf_bits_per_element;
919
920 switch (op->state->phase)
921 {
922 case PHASE_INITIAL:
923 GNUNET_break_op (0);
924 fail_intersection_operation (op);
925 return;
926
927 case PHASE_COUNT_SENT:
928 case PHASE_BF_EXCHANGE:
929 bf_size = ntohl (msg->bloomfilter_total_length);
930 bf_bits_per_element = ntohl (msg->bits_per_element);
931 chunk_size = htons (msg->header.size) - sizeof(struct BFMessage);
932 op->state->other_xor = msg->element_xor_hash;
933 if (bf_size == chunk_size)
934 {
935 if (NULL != op->state->bf_data)
936 {
937 GNUNET_break_op (0);
938 fail_intersection_operation (op);
939 return;
940 }
941 /* single part, done here immediately */
942 op->state->remote_bf
943 = GNUNET_CONTAINER_bloomfilter_init ((const char *) &msg[1],
944 bf_size,
945 bf_bits_per_element);
946 op->state->salt = ntohl (msg->sender_mutator);
947 op->remote_element_count = ntohl (msg->sender_element_count);
948 process_bf (op);
949 break;
950 }
951 /* multipart chunk */
952 if (NULL == op->state->bf_data)
953 {
954 /* first chunk, initialize */
955 op->state->bf_data = GNUNET_malloc (bf_size);
956 op->state->bf_data_size = bf_size;
957 op->state->bf_bits_per_element = bf_bits_per_element;
958 op->state->bf_data_offset = 0;
959 op->state->salt = ntohl (msg->sender_mutator);
960 op->remote_element_count = ntohl (msg->sender_element_count);
961 }
962 else
963 {
964 /* increment */
965 if ((op->state->bf_data_size != bf_size) ||
966 (op->state->bf_bits_per_element != bf_bits_per_element) ||
967 (op->state->bf_data_offset + chunk_size > bf_size) ||
968 (op->state->salt != ntohl (msg->sender_mutator)) ||
969 (op->remote_element_count != ntohl (msg->sender_element_count)))
970 {
971 GNUNET_break_op (0);
972 fail_intersection_operation (op);
973 return;
974 }
975 }
976 GNUNET_memcpy (&op->state->bf_data[op->state->bf_data_offset],
977 (const char *) &msg[1],
978 chunk_size);
979 op->state->bf_data_offset += chunk_size;
980 if (op->state->bf_data_offset == bf_size)
981 {
982 /* last chunk, run! */
983 op->state->remote_bf
984 = GNUNET_CONTAINER_bloomfilter_init (op->state->bf_data,
985 bf_size,
986 bf_bits_per_element);
987 GNUNET_free (op->state->bf_data);
988 op->state->bf_data = NULL;
989 op->state->bf_data_size = 0;
990 process_bf (op);
991 }
992 break;
993
994 default:
995 GNUNET_break_op (0);
996 fail_intersection_operation (op);
997 return;
998 }
999 GNUNET_CADET_receive_done (op->channel);
1000}
1001
1002
1003/**
1004 * Remove all elements from our hashmap.
1005 *
1006 * @param cls closure with the `struct Operation *`
1007 * @param key current key code
1008 * @param value value in the hash map
1009 * @return #GNUNET_YES (we should continue to iterate)
1010 */
1011static int
1012filter_all (void *cls,
1013 const struct GNUNET_HashCode *key,
1014 void *value)
1015{
1016 struct Operation *op = cls;
1017 struct ElementEntry *ee = value;
1018
1019 GNUNET_break (0 < op->state->my_element_count);
1020 op->state->my_element_count--;
1021 GNUNET_CRYPTO_hash_xor (&op->state->my_xor,
1022 &ee->element_hash,
1023 &op->state->my_xor);
1024 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1025 "Final reduction of my_elements, removing %s:%u\n",
1026 GNUNET_h2s (&ee->element_hash),
1027 ee->element.size);
1028 GNUNET_assert (GNUNET_YES ==
1029 GNUNET_CONTAINER_multihashmap_remove (op->state->my_elements,
1030 &ee->element_hash,
1031 ee));
1032 send_client_removed_element (op,
1033 &ee->element);
1034 return GNUNET_YES;
1035}
1036
1037
1038/**
1039 * Handle a done message from a remote peer
1040 *
1041 * @param cls the intersection operation
1042 * @param mh the message
1043 */
1044void
1045handle_intersection_p2p_done (void *cls,
1046 const struct IntersectionDoneMessage *idm)
1047{
1048 struct Operation *op = cls;
1049
1050 if (GNUNET_SET_OPERATION_INTERSECTION != op->set->operation)
1051 {
1052 GNUNET_break_op (0);
1053 fail_intersection_operation (op);
1054 return;
1055 }
1056 if (PHASE_BF_EXCHANGE != op->state->phase)
1057 {
1058 /* wrong phase to conclude? FIXME: Or should we allow this
1059 if the other peer has _initially_ already an empty set? */
1060 GNUNET_break_op (0);
1061 fail_intersection_operation (op);
1062 return;
1063 }
1064 if (0 == ntohl (idm->final_element_count))
1065 {
1066 /* other peer determined empty set is the intersection,
1067 remove all elements */
1068 GNUNET_CONTAINER_multihashmap_iterate (op->state->my_elements,
1069 &filter_all,
1070 op);
1071 }
1072 if ((op->state->my_element_count != ntohl (idm->final_element_count)) ||
1073 (0 != GNUNET_memcmp (&op->state->my_xor,
1074 &idm->element_xor_hash)))
1075 {
1076 /* Other peer thinks we are done, but we disagree on the result! */
1077 GNUNET_break_op (0);
1078 fail_intersection_operation (op);
1079 return;
1080 }
1081 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1082 "Got IntersectionDoneMessage, have %u elements in intersection\n",
1083 op->state->my_element_count);
1084 op->state->phase = PHASE_DONE_RECEIVED;
1085 GNUNET_CADET_receive_done (op->channel);
1086
1087 GNUNET_assert (GNUNET_NO == op->state->client_done_sent);
1088 if (GNUNET_SET_RESULT_FULL == op->result_mode)
1089 {
1090 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1091 "Sending full result set to client (%u elements)\n",
1092 GNUNET_CONTAINER_multihashmap_size (op->state->my_elements));
1093 op->state->full_result_iter
1094 = GNUNET_CONTAINER_multihashmap_iterator_create (op->state->my_elements);
1095 send_remaining_elements (op);
1096 return;
1097 }
1098 op->state->phase = PHASE_FINISHED;
1099 send_client_done_and_destroy (op);
1100}
1101
1102
1103/**
1104 * Initiate a set intersection operation with a remote peer.
1105 *
1106 * @param op operation that is created, should be initialized to
1107 * begin the evaluation
1108 * @param opaque_context message to be transmitted to the listener
1109 * to convince it to accept, may be NULL
1110 * @return operation-specific state to keep in @a op
1111 */
1112static struct OperationState *
1113intersection_evaluate (struct Operation *op,
1114 const struct GNUNET_MessageHeader *opaque_context)
1115{
1116 struct OperationState *state;
1117 struct GNUNET_MQ_Envelope *ev;
1118 struct OperationRequestMessage *msg;
1119
1120 ev = GNUNET_MQ_msg_nested_mh (msg,
1121 GNUNET_MESSAGE_TYPE_SET_P2P_OPERATION_REQUEST,
1122 opaque_context);
1123 if (NULL == ev)
1124 {
1125 /* the context message is too large!? */
1126 GNUNET_break (0);
1127 return NULL;
1128 }
1129 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1130 "Initiating intersection operation evaluation\n");
1131 state = GNUNET_new (struct OperationState);
1132 /* we started the operation, thus we have to send the operation request */
1133 state->phase = PHASE_INITIAL;
1134 state->my_element_count = op->set->state->current_set_element_count;
1135 state->my_elements
1136 = GNUNET_CONTAINER_multihashmap_create (state->my_element_count,
1137 GNUNET_YES);
1138
1139 msg->operation = htonl (GNUNET_SET_OPERATION_INTERSECTION);
1140 msg->element_count = htonl (state->my_element_count);
1141 GNUNET_MQ_send (op->mq,
1142 ev);
1143 state->phase = PHASE_COUNT_SENT;
1144 if (NULL != opaque_context)
1145 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1146 "Sent op request with context message\n");
1147 else
1148 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1149 "Sent op request without context message\n");
1150 return state;
1151}
1152
1153
1154/**
1155 * Accept an intersection operation request from a remote peer. Only
1156 * initializes the private operation state.
1157 *
1158 * @param op operation that will be accepted as an intersection operation
1159 */
1160static struct OperationState *
1161intersection_accept (struct Operation *op)
1162{
1163 struct OperationState *state;
1164
1165 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1166 "Accepting set intersection operation\n");
1167 state = GNUNET_new (struct OperationState);
1168 state->phase = PHASE_INITIAL;
1169 state->my_element_count
1170 = op->set->state->current_set_element_count;
1171 state->my_elements
1172 = GNUNET_CONTAINER_multihashmap_create (GNUNET_MIN (state->my_element_count,
1173 op->remote_element_count),
1174 GNUNET_YES);
1175 op->state = state;
1176 if (op->remote_element_count < state->my_element_count)
1177 {
1178 /* If the other peer (Alice) has fewer elements than us (Bob),
1179 we just send the count as Alice should send the first BF */
1180 send_element_count (op);
1181 state->phase = PHASE_COUNT_SENT;
1182 return state;
1183 }
1184 /* We have fewer elements, so we start with the BF */
1185 begin_bf_exchange (op);
1186 return state;
1187}
1188
1189
1190/**
1191 * Destroy the intersection operation. Only things specific to the
1192 * intersection operation are destroyed.
1193 *
1194 * @param op intersection operation to destroy
1195 */
1196static void
1197intersection_op_cancel (struct Operation *op)
1198{
1199 /* check if the op was canceled twice */
1200 GNUNET_assert (NULL != op->state);
1201 if (NULL != op->state->remote_bf)
1202 {
1203 GNUNET_CONTAINER_bloomfilter_free (op->state->remote_bf);
1204 op->state->remote_bf = NULL;
1205 }
1206 if (NULL != op->state->local_bf)
1207 {
1208 GNUNET_CONTAINER_bloomfilter_free (op->state->local_bf);
1209 op->state->local_bf = NULL;
1210 }
1211 if (NULL != op->state->my_elements)
1212 {
1213 GNUNET_CONTAINER_multihashmap_destroy (op->state->my_elements);
1214 op->state->my_elements = NULL;
1215 }
1216 if (NULL != op->state->full_result_iter)
1217 {
1218 GNUNET_CONTAINER_multihashmap_iterator_destroy (
1219 op->state->full_result_iter);
1220 op->state->full_result_iter = NULL;
1221 }
1222 GNUNET_free (op->state);
1223 op->state = NULL;
1224 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1225 "Destroying intersection op state done\n");
1226}
1227
1228
1229/**
1230 * Create a new set supporting the intersection operation.
1231 *
1232 * @return the newly created set
1233 */
1234static struct SetState *
1235intersection_set_create ()
1236{
1237 struct SetState *set_state;
1238
1239 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1240 "Intersection set created\n");
1241 set_state = GNUNET_new (struct SetState);
1242 set_state->current_set_element_count = 0;
1243
1244 return set_state;
1245}
1246
1247
1248/**
1249 * Add the element from the given element message to the set.
1250 *
1251 * @param set_state state of the set want to add to
1252 * @param ee the element to add to the set
1253 */
1254static void
1255intersection_add (struct SetState *set_state,
1256 struct ElementEntry *ee)
1257{
1258 set_state->current_set_element_count++;
1259}
1260
1261
1262/**
1263 * Destroy a set that supports the intersection operation
1264 *
1265 * @param set_state the set to destroy
1266 */
1267static void
1268intersection_set_destroy (struct SetState *set_state)
1269{
1270 GNUNET_free (set_state);
1271}
1272
1273
1274/**
1275 * Remove the element given in the element message from the set.
1276 *
1277 * @param set_state state of the set to remove from
1278 * @param element set element to remove
1279 */
1280static void
1281intersection_remove (struct SetState *set_state,
1282 struct ElementEntry *element)
1283{
1284 GNUNET_assert (0 < set_state->current_set_element_count);
1285 set_state->current_set_element_count--;
1286}
1287
1288
1289/**
1290 * Callback for channel death for the intersection operation.
1291 *
1292 * @param op operation that lost the channel
1293 */
1294static void
1295intersection_channel_death (struct Operation *op)
1296{
1297 if (GNUNET_YES == op->state->channel_death_expected)
1298 {
1299 /* oh goodie, we are done! */
1300 send_client_done_and_destroy (op);
1301 }
1302 else
1303 {
1304 /* sorry, channel went down early, too bad. */
1305 _GSS_operation_destroy (op,
1306 GNUNET_YES);
1307 }
1308}
1309
1310
1311/**
1312 * Get the table with implementing functions for set intersection.
1313 *
1314 * @return the operation specific VTable
1315 */
1316const struct SetVT *
1317_GSS_intersection_vt ()
1318{
1319 static const struct SetVT intersection_vt = {
1320 .create = &intersection_set_create,
1321 .add = &intersection_add,
1322 .remove = &intersection_remove,
1323 .destroy_set = &intersection_set_destroy,
1324 .evaluate = &intersection_evaluate,
1325 .accept = &intersection_accept,
1326 .cancel = &intersection_op_cancel,
1327 .channel_death = &intersection_channel_death,
1328 };
1329
1330 return &intersection_vt;
1331}
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-16 11:50:11 +0000