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21 * @file src/regex/regex_internal_dht.c
22 * @brief library to announce regexes in the network and match strings
23 * against published regexes.
24 * @author Bartlomiej Polot
27 #include "regex_internal_lib.h"
28 #include "regex_block_lib.h"
29 #include "gnunet_dht_service.h"
30 #include "gnunet_statistics_service.h"
31 #include "gnunet_constants.h"
32 #include "gnunet_signatures.h"
35 #define LOG(kind,...) GNUNET_log_from (kind,"regex-dht",__VA_ARGS__)
38 * DHT replication level to use.
40 #define DHT_REPLICATION 5
43 * DHT record lifetime to use.
45 #define DHT_TTL GNUNET_TIME_UNIT_HOURS
50 #define DHT_OPT GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE
54 * Handle to store cached data about a regex announce.
56 struct REGEX_INTERNAL_Announcement
59 * DHT handle to use, must be initialized externally.
61 struct GNUNET_DHT_Handle *dht;
69 * Automaton representation of the regex (expensive to build).
71 struct REGEX_INTERNAL_Automaton *dfa;
76 const struct GNUNET_CRYPTO_EddsaPrivateKey *priv;
79 * Optional statistics handle to report usage. Can be NULL.
81 struct GNUNET_STATISTICS_Handle *stats;
86 * Regex callback iterator to store own service description in the DHT.
89 * @param key hash for current state.
90 * @param proof proof for current state.
91 * @param accepting #GNUNET_YES if this is an accepting state, #GNUNET_NO if not.
92 * @param num_edges number of edges leaving current state.
93 * @param edges edges leaving current state.
96 regex_iterator (void *cls,
97 const struct GNUNET_HashCode *key,
100 unsigned int num_edges,
101 const struct REGEX_BLOCK_Edge *edges)
103 struct REGEX_INTERNAL_Announcement *h = cls;
104 struct RegexBlock *block;
108 LOG (GNUNET_ERROR_TYPE_INFO,
109 "DHT PUT for state %s with proof `%s' and %u edges:\n",
113 for (i = 0; i < num_edges; i++)
115 LOG (GNUNET_ERROR_TYPE_INFO,
116 "Edge %u `%s' towards %s\n",
119 GNUNET_h2s (&edges[i].destination));
121 if (GNUNET_YES == accepting)
123 struct RegexAcceptBlock ab;
125 LOG (GNUNET_ERROR_TYPE_INFO,
126 "State %s is accepting, putting own id\n",
128 size = sizeof (struct RegexAcceptBlock);
129 ab.purpose.size = ntohl (sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
130 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
131 sizeof (struct GNUNET_HashCode));
132 ab.purpose.purpose = ntohl (GNUNET_SIGNATURE_PURPOSE_REGEX_ACCEPT);
133 ab.expiration_time = GNUNET_TIME_absolute_hton (GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_DHT_MAX_EXPIRATION));
135 GNUNET_CRYPTO_eddsa_key_get_public (h->priv,
136 &ab.peer.public_key);
137 GNUNET_assert (GNUNET_OK ==
138 GNUNET_CRYPTO_eddsa_sign (h->priv,
142 GNUNET_STATISTICS_update (h->stats, "# regex accepting blocks stored",
144 GNUNET_STATISTICS_update (h->stats, "# regex accepting block bytes stored",
145 sizeof (struct RegexAcceptBlock), GNUNET_NO);
147 GNUNET_DHT_put (h->dht, key,
149 DHT_OPT | GNUNET_DHT_RO_RECORD_ROUTE,
150 GNUNET_BLOCK_TYPE_REGEX_ACCEPT,
153 GNUNET_TIME_relative_to_absolute (DHT_TTL),
156 block = REGEX_BLOCK_create (proof,
161 GNUNET_DHT_put (h->dht, key,
164 GNUNET_BLOCK_TYPE_REGEX,
166 GNUNET_TIME_relative_to_absolute (DHT_TTL),
168 GNUNET_STATISTICS_update (h->stats,
169 "# regex blocks stored",
171 GNUNET_STATISTICS_update (h->stats,
172 "# regex block bytes stored",
179 * Announce a regular expression: put all states of the automaton in the DHT.
180 * Does not free resources, must call #REGEX_INTERNAL_announce_cancel() for that.
182 * @param dht An existing and valid DHT service handle. CANNOT be NULL.
183 * @param priv our private key, must remain valid until the announcement is cancelled
184 * @param regex Regular expression to announce.
185 * @param compression How many characters per edge can we squeeze?
186 * @param stats Optional statistics handle to report usage. Can be NULL.
187 * @return Handle to reuse o free cached resources.
188 * Must be freed by calling #REGEX_INTERNAL_announce_cancel().
190 struct REGEX_INTERNAL_Announcement *
191 REGEX_INTERNAL_announce (struct GNUNET_DHT_Handle *dht,
192 const struct GNUNET_CRYPTO_EddsaPrivateKey *priv,
194 uint16_t compression,
195 struct GNUNET_STATISTICS_Handle *stats)
197 struct REGEX_INTERNAL_Announcement *h;
199 GNUNET_assert (NULL != dht);
200 h = GNUNET_new (struct REGEX_INTERNAL_Announcement);
205 h->dfa = REGEX_INTERNAL_construct_dfa (regex, strlen (regex), compression);
206 REGEX_INTERNAL_reannounce (h);
212 * Announce again a regular expression previously announced.
213 * Does use caching to speed up process.
215 * @param h Handle returned by a previous #REGEX_INTERNAL_announce call().
218 REGEX_INTERNAL_reannounce (struct REGEX_INTERNAL_Announcement *h)
220 GNUNET_assert (NULL != h->dfa); /* make sure to call announce first */
221 LOG (GNUNET_ERROR_TYPE_INFO,
222 "REGEX_INTERNAL_reannounce: %s\n",
224 REGEX_INTERNAL_iterate_reachable_edges (h->dfa,
231 * Clear all cached data used by a regex announce.
232 * Does not close DHT connection.
234 * @param h Handle returned by a previous #REGEX_INTERNAL_announce() call.
237 REGEX_INTERNAL_announce_cancel (struct REGEX_INTERNAL_Announcement *h)
239 REGEX_INTERNAL_automaton_destroy (h->dfa);
244 /******************************************************************************/
248 * Struct to keep state of running searches that have consumed a part of
251 struct RegexSearchContext
254 * Part of the description already consumed by
255 * this particular search branch.
260 * Information about the search.
262 struct REGEX_INTERNAL_Search *info;
265 * We just want to look for one edge, the longer the better.
268 unsigned int longest_match;
271 * Destination hash of the longest match.
273 struct GNUNET_HashCode hash;
278 * Type of values in `dht_get_results`.
283 * Number of bytes in data.
288 * The raw result data.
295 * Struct to keep information of searches of services described by a regex
296 * using a user-provided string service description.
298 struct REGEX_INTERNAL_Search
301 * DHT handle to use, must be initialized externally.
303 struct GNUNET_DHT_Handle *dht;
306 * Optional statistics handle to report usage. Can be NULL.
308 struct GNUNET_STATISTICS_Handle *stats;
311 * User provided description of the searched service.
318 struct GNUNET_CONTAINER_MultiHashMap *dht_get_handles;
321 * Results from running DHT GETs, values are of type
324 struct GNUNET_CONTAINER_MultiHashMap *dht_get_results;
327 * Contexts, for each running DHT GET. Free all on end of search.
329 struct RegexSearchContext **contexts;
332 * Number of contexts (branches/steps in search).
334 unsigned int n_contexts;
337 * @param callback Callback for found peers.
339 REGEX_INTERNAL_Found callback;
342 * @param callback_cls Closure for @c callback.
349 * Jump to the next edge, with the longest matching token.
351 * @param block Block found in the DHT.
352 * @param size Size of the block.
353 * @param ctx Context of the search.
356 regex_next_edge (const struct RegexBlock *block,
358 struct RegexSearchContext *ctx);
362 * Function to process DHT string to regex matching.
363 * Called on each result obtained for the DHT search.
365 * @param cls Closure (search context).
366 * @param exp When will this value expire.
367 * @param key Key of the result.
368 * @param get_path Path of the get request.
369 * @param get_path_length Lenght of get_path.
370 * @param put_path Path of the put request.
371 * @param put_path_length Length of the put_path.
372 * @param type Type of the result.
373 * @param size Number of bytes in data.
374 * @param data Pointer to the result data.
377 dht_get_string_accept_handler (void *cls, struct GNUNET_TIME_Absolute exp,
378 const struct GNUNET_HashCode *key,
379 const struct GNUNET_PeerIdentity *get_path,
380 unsigned int get_path_length,
381 const struct GNUNET_PeerIdentity *put_path,
382 unsigned int put_path_length,
383 enum GNUNET_BLOCK_Type type,
384 size_t size, const void *data)
386 const struct RegexAcceptBlock *block = data;
387 struct RegexSearchContext *ctx = cls;
388 struct REGEX_INTERNAL_Search *info = ctx->info;
390 LOG (GNUNET_ERROR_TYPE_DEBUG,
391 "Regex result accept for %s (key %s)\n",
392 info->description, GNUNET_h2s(key));
394 GNUNET_STATISTICS_update (info->stats,
395 "# regex accepting blocks found",
397 GNUNET_STATISTICS_update (info->stats,
398 "# regex accepting block bytes found",
400 info->callback (info->callback_cls,
402 get_path, get_path_length,
403 put_path, put_path_length);
408 * Find a path to a peer that offers a regex service compatible
409 * with a given string.
411 * @param key The key of the accepting state.
412 * @param ctx Context containing info about the string, tunnel, etc.
415 regex_find_path (const struct GNUNET_HashCode *key,
416 struct RegexSearchContext *ctx)
418 struct GNUNET_DHT_GetHandle *get_h;
420 LOG (GNUNET_ERROR_TYPE_DEBUG,
421 "Accept state found, now searching for paths to %s\n",
423 (unsigned int) ctx->position);
424 get_h = GNUNET_DHT_get_start (ctx->info->dht, /* handle */
425 GNUNET_BLOCK_TYPE_REGEX_ACCEPT, /* type */
426 key, /* key to search */
427 DHT_REPLICATION, /* replication level */
428 DHT_OPT | GNUNET_DHT_RO_RECORD_ROUTE,
429 NULL, /* xquery */ // FIXME BLOOMFILTER
430 0, /* xquery bits */ // FIXME BLOOMFILTER SIZE
431 &dht_get_string_accept_handler, ctx);
432 GNUNET_break (GNUNET_OK ==
433 GNUNET_CONTAINER_multihashmap_put(ctx->info->dht_get_handles,
436 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE));
441 * Function to process DHT string to regex matching.
442 * Called on each result obtained for the DHT search.
444 * @param cls closure (search context)
445 * @param exp when will this value expire
446 * @param key key of the result
447 * @param get_path path of the get request (not used)
448 * @param get_path_length length of @a get_path (not used)
449 * @param put_path path of the put request (not used)
450 * @param put_path_length length of the @a put_path (not used)
451 * @param type type of the result
452 * @param size number of bytes in data
453 * @param data pointer to the result data
455 * TODO: re-issue the request after certain time? cancel after X results?
458 dht_get_string_handler (void *cls, struct GNUNET_TIME_Absolute exp,
459 const struct GNUNET_HashCode *key,
460 const struct GNUNET_PeerIdentity *get_path,
461 unsigned int get_path_length,
462 const struct GNUNET_PeerIdentity *put_path,
463 unsigned int put_path_length,
464 enum GNUNET_BLOCK_Type type,
465 size_t size, const void *data)
467 const struct RegexBlock *block = data;
468 struct RegexSearchContext *ctx = cls;
469 struct REGEX_INTERNAL_Search *info = ctx->info;
473 LOG (GNUNET_ERROR_TYPE_INFO,
474 "DHT GET result for %s (%s)\n",
475 GNUNET_h2s (key), ctx->info->description);
476 copy = GNUNET_malloc (sizeof (struct Result) + size);
478 copy->data = ©[1];
479 GNUNET_memcpy (©[1], block, size);
480 GNUNET_break (GNUNET_OK ==
481 GNUNET_CONTAINER_multihashmap_put (info->dht_get_results,
483 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE));
484 len = strlen (info->description);
485 if (len == ctx->position) // String processed
487 if (GNUNET_YES == GNUNET_BLOCK_is_accepting (block, size))
489 regex_find_path (key, ctx);
493 LOG (GNUNET_ERROR_TYPE_INFO, "block not accepting!\n");
494 /* FIXME REGEX this block not successful, wait for more? start timeout? */
498 regex_next_edge (block, size, ctx);
503 * Iterator over found existing cadet regex blocks that match an ongoing search.
505 * @param cls Closure (current context)-
506 * @param key Current key code (key for cached block).
507 * @param value Value in the hash map (cached RegexBlock).
508 * @return #GNUNET_YES: we should always continue to iterate.
511 regex_result_iterator (void *cls,
512 const struct GNUNET_HashCode * key,
515 struct Result *result = value;
516 const struct RegexBlock *block = result->data;
517 struct RegexSearchContext *ctx = cls;
520 GNUNET_BLOCK_is_accepting (block, result->size)) &&
521 (ctx->position == strlen (ctx->info->description)) )
523 LOG (GNUNET_ERROR_TYPE_INFO,
524 "Found accepting known block\n");
525 regex_find_path (key, ctx);
526 return GNUNET_YES; // We found an accept state!
528 LOG (GNUNET_ERROR_TYPE_DEBUG,
531 strlen (ctx->info->description),
532 GNUNET_BLOCK_is_accepting (block, result->size));
533 regex_next_edge (block, result->size, ctx);
535 GNUNET_STATISTICS_update (ctx->info->stats, "# regex cadet blocks iterated",
543 * Iterator over edges in a regex block retrieved from the DHT.
545 * @param cls Closure (context of the search).
546 * @param token Token that follows to next state.
547 * @param len Lenght of token.
548 * @param key Hash of next state.
549 * @return #GNUNET_YES if should keep iterating, #GNUNET_NO otherwise.
552 regex_edge_iterator (void *cls,
555 const struct GNUNET_HashCode *key)
557 struct RegexSearchContext *ctx = cls;
558 struct REGEX_INTERNAL_Search *info = ctx->info;
562 GNUNET_STATISTICS_update (info->stats, "# regex edges iterated",
564 current = &info->description[ctx->position];
565 current_len = strlen (info->description) - ctx->position;
566 if (len > current_len)
568 LOG (GNUNET_ERROR_TYPE_DEBUG, "Token too long, END\n");
571 if (0 != strncmp (current, token, len))
573 LOG (GNUNET_ERROR_TYPE_DEBUG, "Token doesn't match, END\n");
577 if (len > ctx->longest_match)
579 LOG (GNUNET_ERROR_TYPE_DEBUG, "Token is longer, KEEP\n");
580 ctx->longest_match = len;
585 LOG (GNUNET_ERROR_TYPE_DEBUG, "Token is not longer, IGNORE\n");
588 LOG (GNUNET_ERROR_TYPE_DEBUG, "* End of regex edge iterator\n");
594 * Jump to the next edge, with the longest matching token.
596 * @param block Block found in the DHT.
597 * @param size Size of the block.
598 * @param ctx Context of the search.
601 regex_next_edge (const struct RegexBlock *block,
603 struct RegexSearchContext *ctx)
605 struct RegexSearchContext *new_ctx;
606 struct REGEX_INTERNAL_Search *info = ctx->info;
607 struct GNUNET_DHT_GetHandle *get_h;
608 struct GNUNET_HashCode *hash;
612 LOG (GNUNET_ERROR_TYPE_DEBUG, "Next edge\n");
613 /* Find the longest match for the current string position,
614 * among tokens in the given block */
615 ctx->longest_match = 0;
616 result = REGEX_BLOCK_iterate (block, size,
617 ®ex_edge_iterator, ctx);
618 GNUNET_break (GNUNET_OK == result);
620 /* Did anything match? */
621 if (0 == ctx->longest_match)
623 LOG (GNUNET_ERROR_TYPE_DEBUG,
624 "no match in block\n");
629 new_ctx = GNUNET_new (struct RegexSearchContext);
630 new_ctx->info = info;
631 new_ctx->position = ctx->position + ctx->longest_match;
632 GNUNET_array_append (info->contexts, info->n_contexts, new_ctx);
634 /* Check whether we already have a DHT GET running for it */
636 GNUNET_CONTAINER_multihashmap_contains (info->dht_get_handles, hash))
638 LOG (GNUNET_ERROR_TYPE_DEBUG,
639 "GET for %s running, END\n",
641 GNUNET_CONTAINER_multihashmap_get_multiple (info->dht_get_results,
643 ®ex_result_iterator,
645 return; /* We are already looking for it */
648 GNUNET_STATISTICS_update (info->stats, "# regex nodes traversed",
651 LOG (GNUNET_ERROR_TYPE_DEBUG,
652 "Following edges at %s for offset %u in `%s'\n",
654 (unsigned int) ctx->position,
656 rest = &new_ctx->info->description[new_ctx->position];
658 GNUNET_DHT_get_start (info->dht, /* handle */
659 GNUNET_BLOCK_TYPE_REGEX, /* type */
660 hash, /* key to search */
661 DHT_REPLICATION, /* replication level */
664 strlen (rest) + 1, /* xquery bits */
665 &dht_get_string_handler, new_ctx);
667 GNUNET_CONTAINER_multihashmap_put(info->dht_get_handles,
670 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
679 * Search for a peer offering a regex matching certain string in the DHT.
680 * The search runs until #REGEX_INTERNAL_search_cancel() is called, even if results
683 * @param dht An existing and valid DHT service handle.
684 * @param string String to match against the regexes in the DHT.
685 * @param callback Callback for found peers.
686 * @param callback_cls Closure for @c callback.
687 * @param stats Optional statistics handle to report usage. Can be NULL.
688 * @return Handle to stop search and free resources.
689 * Must be freed by calling #REGEX_INTERNAL_search_cancel().
691 struct REGEX_INTERNAL_Search *
692 REGEX_INTERNAL_search (struct GNUNET_DHT_Handle *dht,
694 REGEX_INTERNAL_Found callback,
696 struct GNUNET_STATISTICS_Handle *stats)
698 struct REGEX_INTERNAL_Search *h;
699 struct GNUNET_DHT_GetHandle *get_h;
700 struct RegexSearchContext *ctx;
701 struct GNUNET_HashCode key;
705 /* Initialize handle */
706 GNUNET_assert (NULL != dht);
707 GNUNET_assert (NULL != callback);
708 h = GNUNET_new (struct REGEX_INTERNAL_Search);
710 h->description = GNUNET_strdup (string);
711 h->callback = callback;
712 h->callback_cls = callback_cls;
714 h->dht_get_handles = GNUNET_CONTAINER_multihashmap_create (32, GNUNET_NO);
715 h->dht_get_results = GNUNET_CONTAINER_multihashmap_create (32, GNUNET_NO);
717 /* Initialize context */
718 len = strlen (string);
719 size = REGEX_INTERNAL_get_first_key (string, len, &key);
720 LOG (GNUNET_ERROR_TYPE_INFO,
721 "Initial key for `%s' is %s (based on `%.*s')\n",
726 ctx = GNUNET_new (struct RegexSearchContext);
727 ctx->position = size;
729 GNUNET_array_append (h->contexts,
732 /* Start search in DHT */
733 get_h = GNUNET_DHT_get_start (h->dht, /* handle */
734 GNUNET_BLOCK_TYPE_REGEX, /* type */
735 &key, /* key to search */
736 DHT_REPLICATION, /* replication level */
738 &h->description[size], /* xquery */
739 // FIXME add BLOOMFILTER to exclude filtered peers
740 len + 1 - size, /* xquery bits */
741 // FIXME add BLOOMFILTER SIZE
742 &dht_get_string_handler, ctx);
745 GNUNET_CONTAINER_multihashmap_put (h->dht_get_handles,
748 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST)
756 * Iterator over hash map entries to cancel DHT GET requests after a
757 * successful connect_by_string.
759 * @param cls Closure (unused).
760 * @param key Current key code (unused).
761 * @param value Value in the hash map (get handle).
762 * @return #GNUNET_YES if we should continue to iterate,
766 regex_cancel_dht_get (void *cls,
767 const struct GNUNET_HashCode * key,
770 struct GNUNET_DHT_GetHandle *h = value;
772 GNUNET_DHT_get_stop (h);
778 * Iterator over hash map entries to free CadetRegexBlocks stored during the
779 * search for connect_by_string.
781 * @param cls Closure (unused).
782 * @param key Current key code (unused).
783 * @param value CadetRegexBlock in the hash map.
784 * @return #GNUNET_YES if we should continue to iterate,
788 regex_free_result (void *cls,
789 const struct GNUNET_HashCode * key,
798 * Cancel an ongoing regex search in the DHT and free all resources.
800 * @param h the search context.
803 REGEX_INTERNAL_search_cancel (struct REGEX_INTERNAL_Search *h)
807 GNUNET_free (h->description);
808 GNUNET_CONTAINER_multihashmap_iterate (h->dht_get_handles,
809 ®ex_cancel_dht_get, NULL);
810 GNUNET_CONTAINER_multihashmap_iterate (h->dht_get_results,
811 ®ex_free_result, NULL);
812 GNUNET_CONTAINER_multihashmap_destroy (h->dht_get_results);
813 GNUNET_CONTAINER_multihashmap_destroy (h->dht_get_handles);
814 if (0 < h->n_contexts)
816 for (i = 0; i < h->n_contexts; i++)
817 GNUNET_free (h->contexts[i]);
818 GNUNET_free (h->contexts);
824 /* end of regex_internal_dht.c */