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3 (C) 2012 Christian Grothoff (and other contributing authors)
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21 * @file src/regex/regex_dht.c
22 * @brief library to announce regexes in the network and match strings
23 * against published regexes.
24 * @author Bartlomiej Polot
27 #include "gnunet_regex_lib.h"
28 #include "regex_block_lib.h"
29 #include "gnunet_dht_service.h"
30 #include "gnunet_statistics_service.h"
32 #define LOG(kind,...) GNUNET_log_from (kind,"regex-dht",__VA_ARGS__)
34 /* FIXME: OPTION (API, CONFIG) */
35 #define DHT_REPLICATION 5
36 #define DHT_TTL GNUNET_TIME_UNIT_HOURS
37 #define DEBUG_DHT GNUNET_YES
40 #define DHT_OPT GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE | GNUNET_DHT_RO_RECORD_ROUTE
42 #define DHT_OPT GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE
45 struct GNUNET_REGEX_announce_handle
48 * DHT handle to use, must be initialized externally.
50 struct GNUNET_DHT_Handle *dht;
58 * Automaton representation of the regex (expensive to build).
60 struct GNUNET_REGEX_Automaton* dfa;
63 * Identity under which to announce the regex.
65 struct GNUNET_PeerIdentity *id;
68 * Optional statistics handle to report usage. Can be NULL.
70 struct GNUNET_STATISTICS_Handle *stats;
75 * Regex callback iterator to store own service description in the DHT.
78 * @param key hash for current state.
79 * @param proof proof for current state.
80 * @param accepting GNUNET_YES if this is an accepting state, GNUNET_NO if not.
81 * @param num_edges number of edges leaving current state.
82 * @param edges edges leaving current state.
85 regex_iterator (void *cls,
86 const struct GNUNET_HashCode *key,
89 unsigned int num_edges,
90 const struct GNUNET_REGEX_Edge *edges)
92 struct GNUNET_REGEX_announce_handle *h = cls;
93 struct RegexBlock *block;
94 struct RegexEdge *block_edge;
101 LOG (GNUNET_ERROR_TYPE_DEBUG,
102 " regex dht put for state %s\n",
104 LOG (GNUNET_ERROR_TYPE_DEBUG, " proof: %s\n", proof);
105 LOG (GNUNET_ERROR_TYPE_DEBUG, " num edges: %u\n", num_edges);
107 if (GNUNET_YES == accepting)
109 struct RegexAccept block;
111 LOG (GNUNET_ERROR_TYPE_DEBUG,
112 " state %s is accepting, putting own id\n",
114 size = sizeof (block);
117 GNUNET_STATISTICS_update (h->stats, "# regex accepting blocks stored",
119 GNUNET_STATISTICS_update (h->stats, "# regex accepting block bytes stored",
120 sizeof (block), GNUNET_NO);
122 GNUNET_DHT_put (h->dht, key,
124 DHT_OPT | GNUNET_DHT_RO_RECORD_ROUTE,
125 GNUNET_BLOCK_TYPE_REGEX_ACCEPT,
128 GNUNET_TIME_relative_to_absolute (DHT_TTL),
133 size = sizeof (struct RegexBlock) + len;
134 block = GNUNET_malloc (size);
137 block->n_proof = htonl (len);
138 block->n_edges = htonl (num_edges);
139 block->accepting = htonl (accepting);
141 /* Store the proof at the end of the block. */
142 aux = (char *) &block[1];
143 memcpy (aux, proof, len);
146 /* Store each edge in a variable length MeshEdge struct at the
147 * very end of the MeshRegexBlock structure.
149 for (i = 0; i < num_edges; i++)
151 LOG (GNUNET_ERROR_TYPE_DEBUG, " edge %s towards %s\n",
152 edges[i].label, GNUNET_h2s(&edges[i].destination));
154 /* aux points at the end of the last block */
155 len = strlen (edges[i].label);
156 size += sizeof (struct RegexEdge) + len;
157 // Calculate offset FIXME is this ok? use size instead?
158 offset = aux - (char *) block;
159 block = GNUNET_realloc (block, size);
160 aux = &((char *) block)[offset];
161 block_edge = (struct RegexEdge *) aux;
162 block_edge->key = edges[i].destination;
163 block_edge->n_token = htonl (len);
164 aux = (char *) &block_edge[1];
165 memcpy (aux, edges[i].label, len);
169 GNUNET_DHT_put (h->dht, key,
172 GNUNET_BLOCK_TYPE_REGEX, size,
174 GNUNET_TIME_relative_to_absolute (DHT_TTL),
177 GNUNET_STATISTICS_update (h->stats, "# regex blocks stored",
179 GNUNET_STATISTICS_update (h->stats, "# regex block bytes stored",
186 struct GNUNET_REGEX_announce_handle *
187 GNUNET_REGEX_announce (struct GNUNET_DHT_Handle *dht,
188 struct GNUNET_PeerIdentity *id,
190 uint16_t compression,
191 struct GNUNET_STATISTICS_Handle *stats)
193 struct GNUNET_REGEX_announce_handle *h;
195 GNUNET_assert (NULL != dht);
196 h = GNUNET_malloc (sizeof (struct GNUNET_REGEX_announce_handle));
201 h->dfa = GNUNET_REGEX_construct_dfa (regex,
204 GNUNET_REGEX_reannounce (h);
209 GNUNET_REGEX_reannounce (struct GNUNET_REGEX_announce_handle *h)
211 LOG (GNUNET_ERROR_TYPE_INFO, "GNUNET_REGEX_reannounce: %s\n", h->regex);
212 GNUNET_REGEX_iterate_all_edges (h->dfa, ®ex_iterator, h);
216 GNUNET_REGEX_announce_cancel (struct GNUNET_REGEX_announce_handle *h)
218 GNUNET_REGEX_automaton_destroy (h->dfa);
223 /******************************************************************************/
227 * Struct to keep state of running searches that have consumed a part of
230 struct RegexSearchContext
233 * Part of the description already consumed by
234 * this particular search branch.
239 * Information about the search.
241 struct GNUNET_REGEX_search_handle *info;
244 * We just want to look for one edge, the longer the better.
247 unsigned int longest_match;
250 * Destination hash of the longest match.
252 struct GNUNET_HashCode hash;
257 * Struct to keep information of searches of services described by a regex
258 * using a user-provided string service description.
260 struct GNUNET_REGEX_search_handle
263 * DHT handle to use, must be initialized externally.
265 struct GNUNET_DHT_Handle *dht;
268 * Optional statistics handle to report usage. Can be NULL.
270 struct GNUNET_STATISTICS_Handle *stats;
273 * User provided description of the searched service.
280 struct GNUNET_CONTAINER_MultiHashMap *dht_get_handles;
283 * Results from running DHT GETs.
285 struct GNUNET_CONTAINER_MultiHashMap *dht_get_results;
288 * Contexts, for each running DHT GET. Free all on end of search.
290 struct RegexSearchContext **contexts;
293 * Number of contexts (branches/steps in search).
295 unsigned int n_contexts;
298 * @param callback Callback for found peers.
300 GNUNET_REGEX_Found callback;
303 * @param callback_cls Closure for @c callback.
311 * Jump to the next edge, with the longest matching token.
313 * @param block Block found in the DHT.
314 * @param size Size of the block.
315 * @param ctx Context of the search.
317 * @return GNUNET_YES if should keep iterating, GNUNET_NO otherwise.
320 regex_next_edge (const struct RegexBlock *block,
322 struct RegexSearchContext *ctx);
326 * Function to process DHT string to regex matching.
327 * Called on each result obtained for the DHT search.
329 * @param cls Closure (search context).
330 * @param exp When will this value expire.
331 * @param key Key of the result.
332 * @param get_path Path of the get request.
333 * @param get_path_length Lenght of get_path.
334 * @param put_path Path of the put request.
335 * @param put_path_length Length of the put_path.
336 * @param type Type of the result.
337 * @param size Number of bytes in data.
338 * @param data Pointer to the result data.
341 dht_get_string_accept_handler (void *cls, struct GNUNET_TIME_Absolute exp,
342 const struct GNUNET_HashCode * key,
343 const struct GNUNET_PeerIdentity *get_path,
344 unsigned int get_path_length,
345 const struct GNUNET_PeerIdentity *put_path,
346 unsigned int put_path_length,
347 enum GNUNET_BLOCK_Type type,
348 size_t size, const void *data)
350 const struct RegexAccept *block = data;
351 struct RegexSearchContext *ctx = cls;
352 struct GNUNET_REGEX_search_handle *info = ctx->info;
354 LOG (GNUNET_ERROR_TYPE_DEBUG, "Got regex results from DHT!\n");
355 LOG (GNUNET_ERROR_TYPE_INFO, " accept for %s (key %s)\n",
356 info->description, GNUNET_h2s(key));
358 GNUNET_STATISTICS_update (info->stats, "# regex accepting blocks found",
360 GNUNET_STATISTICS_update (info->stats, "# regex accepting block bytes found",
363 info->callback (info->callback_cls,
365 get_path, get_path_length,
366 put_path, put_path_length);
372 * Find a path to a peer that offers a regex servcie compatible
373 * with a given string.
375 * @param key The key of the accepting state.
376 * @param ctx Context containing info about the string, tunnel, etc.
379 regex_find_path (const struct GNUNET_HashCode *key,
380 struct RegexSearchContext *ctx)
382 struct GNUNET_DHT_GetHandle *get_h;
384 LOG (GNUNET_ERROR_TYPE_DEBUG, "Found peer by service\n");
385 LOG (GNUNET_ERROR_TYPE_INFO, " find accept for %s\n", GNUNET_h2s (key));
386 get_h = GNUNET_DHT_get_start (ctx->info->dht, /* handle */
387 GNUNET_BLOCK_TYPE_REGEX_ACCEPT, /* type */
388 key, /* key to search */
389 DHT_REPLICATION, /* replication level */
390 DHT_OPT | GNUNET_DHT_RO_RECORD_ROUTE,
391 NULL, /* xquery */ // FIXME BLOOMFILTER
392 0, /* xquery bits */ // FIXME BLOOMFILTER SIZE
393 &dht_get_string_accept_handler, ctx);
394 GNUNET_break (GNUNET_OK ==
395 GNUNET_CONTAINER_multihashmap_put(ctx->info->dht_get_handles,
398 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE));
403 * Function to process DHT string to regex matching.
404 * Called on each result obtained for the DHT search.
406 * @param cls closure (search context)
407 * @param exp when will this value expire
408 * @param key key of the result
409 * @param get_path path of the get request (not used)
410 * @param get_path_length lenght of get_path (not used)
411 * @param put_path path of the put request (not used)
412 * @param put_path_length length of the put_path (not used)
413 * @param type type of the result
414 * @param size number of bytes in data
415 * @param data pointer to the result data
417 * TODO: re-issue the request after certain time? cancel after X results?
420 dht_get_string_handler (void *cls, struct GNUNET_TIME_Absolute exp,
421 const struct GNUNET_HashCode * key,
422 const struct GNUNET_PeerIdentity *get_path,
423 unsigned int get_path_length,
424 const struct GNUNET_PeerIdentity *put_path,
425 unsigned int put_path_length,
426 enum GNUNET_BLOCK_Type type,
427 size_t size, const void *data)
429 const struct RegexBlock *block = data;
430 struct RegexSearchContext *ctx = cls;
431 struct GNUNET_REGEX_search_handle *info = ctx->info;
437 if (NULL != put_path && 0 != put_path_length)
439 datastore = GNUNET_strdup (GNUNET_i2s (&put_path[put_path_length - 1]));
443 GNUNET_asprintf (&datastore, "?? %u/%u", put_path_length, get_path_length);
446 datastore = GNUNET_strdup ("N/A");
449 LOG (GNUNET_ERROR_TYPE_INFO, " DHT GET result for %s (%s) at %s\n",
450 GNUNET_h2s (key), ctx->info->description, datastore);
451 GNUNET_free (datastore);
453 copy = GNUNET_malloc (size);
454 memcpy (copy, data, size);
457 GNUNET_CONTAINER_multihashmap_put (info->dht_get_results, key, copy,
458 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE)
460 len = ntohl (block->n_proof);
464 memcpy (proof, &block[1], len);
466 if (GNUNET_OK != GNUNET_REGEX_check_proof (proof, key))
472 len = strlen (info->description);
473 if (len == ctx->position) // String processed
475 if (GNUNET_YES == ntohl (block->accepting))
477 regex_find_path (key, ctx);
481 LOG (GNUNET_ERROR_TYPE_INFO, " block not accepting!\n");
482 // FIXME REGEX this block not successful, wait for more? start timeout?
487 regex_next_edge (block, size, ctx);
494 * Iterator over found existing mesh regex blocks that match an ongoing search.
496 * @param cls Closure (current context)-
497 * @param key Current key code (key for cached block).
498 * @param value Value in the hash map (cached RegexBlock).
499 * @return GNUNET_YES: we should always continue to iterate.
502 regex_result_iterator (void *cls,
503 const struct GNUNET_HashCode * key,
506 struct RegexBlock *block = value;
507 struct RegexSearchContext *ctx = cls;
509 if (GNUNET_YES == ntohl(block->accepting) &&
510 ctx->position == strlen (ctx->info->description))
512 LOG (GNUNET_ERROR_TYPE_INFO, " * Found accepting known block\n");
513 regex_find_path (key, ctx);
514 return GNUNET_YES; // We found an accept state!
516 LOG (GNUNET_ERROR_TYPE_DEBUG, "* %u, %u, [%u]\n",
517 ctx->position, strlen(ctx->info->description),
518 ntohl(block->accepting));
520 regex_next_edge (block, SIZE_MAX, ctx);
522 GNUNET_STATISTICS_update (ctx->info->stats, "# regex mesh blocks iterated",
530 * Iterator over edges in a regex block retrieved from the DHT.
532 * @param cls Closure (context of the search).
533 * @param token Token that follows to next state.
534 * @param len Lenght of token.
535 * @param key Hash of next state.
537 * @return GNUNET_YES if should keep iterating, GNUNET_NO otherwise.
540 regex_edge_iterator (void *cls,
543 const struct GNUNET_HashCode *key)
545 struct RegexSearchContext *ctx = cls;
546 struct GNUNET_REGEX_search_handle *info = ctx->info;
550 GNUNET_STATISTICS_update (info->stats, "# regex edges iterated",
553 LOG (GNUNET_ERROR_TYPE_DEBUG, "* Start of regex edge iterator\n");
554 LOG (GNUNET_ERROR_TYPE_DEBUG, "* descr : %s\n", info->description);
555 LOG (GNUNET_ERROR_TYPE_DEBUG, "* posit : %u\n", ctx->position);
556 current = &info->description[ctx->position];
557 LOG (GNUNET_ERROR_TYPE_DEBUG, "* currt : %s\n", current);
558 current_len = strlen (info->description) - ctx->position;
559 LOG (GNUNET_ERROR_TYPE_DEBUG, "* ctlen : %u\n", current_len);
560 LOG (GNUNET_ERROR_TYPE_DEBUG, "* tklen : %u\n", len);
561 LOG (GNUNET_ERROR_TYPE_DEBUG, "* token : %.*s\n", len, token);
562 LOG (GNUNET_ERROR_TYPE_DEBUG, "* nextk : %s\n", GNUNET_h2s(key));
563 if (len > current_len)
565 LOG (GNUNET_ERROR_TYPE_DEBUG, "* Token too long, END\n");
566 return GNUNET_YES; // Token too long, wont match
568 if (0 != strncmp (current, token, len))
570 LOG (GNUNET_ERROR_TYPE_DEBUG, "* Token doesn't match, END\n");
571 return GNUNET_YES; // Token doesn't match
574 if (len > ctx->longest_match)
576 LOG (GNUNET_ERROR_TYPE_DEBUG, "* Token is longer, KEEP\n");
577 ctx->longest_match = len;
582 LOG (GNUNET_ERROR_TYPE_DEBUG, "* Token is not longer, IGNORE\n");
585 LOG (GNUNET_ERROR_TYPE_DEBUG, "* End of regex edge iterator\n");
591 * Jump to the next edge, with the longest matching token.
593 * @param block Block found in the DHT.
594 * @param size Size of the block.
595 * @param ctx Context of the search.
597 * @return GNUNET_YES if should keep iterating, GNUNET_NO otherwise.
600 regex_next_edge (const struct RegexBlock *block,
602 struct RegexSearchContext *ctx)
604 struct RegexSearchContext *new_ctx;
605 struct GNUNET_REGEX_search_handle *info = ctx->info;
606 struct GNUNET_DHT_GetHandle *get_h;
607 struct GNUNET_HashCode *hash;
611 /* Find the longest match for the current string position,
612 * among tokens in the given block */
613 ctx->longest_match = 0;
614 result = GNUNET_REGEX_block_iterate (block, size,
615 ®ex_edge_iterator, ctx);
616 GNUNET_break (GNUNET_OK == result);
618 /* Did anything match? */
619 if (0 == ctx->longest_match)
621 LOG (GNUNET_ERROR_TYPE_DEBUG, " no match in block\n");
626 new_ctx = GNUNET_malloc (sizeof (struct RegexSearchContext));
627 new_ctx->info = info;
628 new_ctx->position = ctx->position + ctx->longest_match;
629 GNUNET_array_append (info->contexts, info->n_contexts, new_ctx);
631 /* Check whether we already have a DHT GET running for it */
633 GNUNET_CONTAINER_multihashmap_contains (info->dht_get_handles, hash))
635 LOG (GNUNET_ERROR_TYPE_DEBUG, "* GET running, END\n");
636 GNUNET_CONTAINER_multihashmap_get_multiple (info->dht_get_results,
638 ®ex_result_iterator,
640 return; /* We are already looking for it */
643 GNUNET_STATISTICS_update (info->stats, "# regex nodes traversed",
646 /* Start search in DHT */
647 LOG (GNUNET_ERROR_TYPE_INFO, " looking for %s\n", GNUNET_h2s (hash));
648 rest = &new_ctx->info->description[new_ctx->position];
650 GNUNET_DHT_get_start (info->dht, /* handle */
651 GNUNET_BLOCK_TYPE_REGEX, /* type */
652 hash, /* key to search */
653 DHT_REPLICATION, /* replication level */
656 // FIXME add BLOOMFILTER to exclude filtered peers
657 strlen(rest) + 1, /* xquery bits */
658 // FIXME add BLOOMFILTER SIZE
659 &dht_get_string_handler, new_ctx);
661 GNUNET_CONTAINER_multihashmap_put(info->dht_get_handles,
664 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
672 struct GNUNET_REGEX_search_handle *
673 GNUNET_REGEX_search (struct GNUNET_DHT_Handle *dht,
675 GNUNET_REGEX_Found callback,
677 struct GNUNET_STATISTICS_Handle *stats)
679 struct GNUNET_REGEX_search_handle *h;
680 struct GNUNET_DHT_GetHandle *get_h;
681 struct RegexSearchContext *ctx;
682 struct GNUNET_HashCode key;
686 /* Initialize handle */
687 LOG (GNUNET_ERROR_TYPE_INFO, "GNUNET_REGEX_search: %s\n", string);
688 GNUNET_assert (NULL != dht);
689 GNUNET_assert (NULL != callback);
690 h = GNUNET_malloc (sizeof (struct GNUNET_REGEX_search_handle));
692 h->description = GNUNET_strdup (string);
693 h->callback = callback;
694 h->callback_cls = callback_cls;
696 h->dht_get_handles = GNUNET_CONTAINER_multihashmap_create (32, GNUNET_YES);
697 h->dht_get_results = GNUNET_CONTAINER_multihashmap_create (32, GNUNET_YES);
699 /* Initialize context */
700 len = strlen (string);
701 size = GNUNET_REGEX_get_first_key (string, len, &key);
702 ctx = GNUNET_malloc (sizeof (struct RegexSearchContext));
703 ctx->position = size;
705 GNUNET_array_append (h->contexts, h->n_contexts, ctx);
706 LOG (GNUNET_ERROR_TYPE_DEBUG, " consumed %u bits out of %u\n", size, len);
707 LOG (GNUNET_ERROR_TYPE_INFO, " looking for %s\n", GNUNET_h2s (&key));
709 /* Start search in DHT */
710 get_h = GNUNET_DHT_get_start (h->dht, /* handle */
711 GNUNET_BLOCK_TYPE_REGEX, /* type */
712 &key, /* key to search */
713 DHT_REPLICATION, /* replication level */
715 &h->description[size], /* xquery */
716 // FIXME add BLOOMFILTER to exclude filtered peers
717 len + 1 - size, /* xquery bits */
718 // FIXME add BLOOMFILTER SIZE
719 &dht_get_string_handler, ctx);
722 GNUNET_CONTAINER_multihashmap_put (h->dht_get_handles,
725 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST)
733 * Iterator over hash map entries to cancel DHT GET requests after a
734 * successful connect_by_string.
736 * @param cls Closure (unused).
737 * @param key Current key code (unused).
738 * @param value Value in the hash map (get handle).
739 * @return GNUNET_YES if we should continue to iterate,
743 regex_cancel_dht_get (void *cls,
744 const struct GNUNET_HashCode * key,
747 struct GNUNET_DHT_GetHandle *h = value;
749 GNUNET_DHT_get_stop (h);
755 * Iterator over hash map entries to free MeshRegexBlocks stored during the
756 * search for connect_by_string.
758 * @param cls Closure (unused).
759 * @param key Current key code (unused).
760 * @param value MeshRegexBlock in the hash map.
761 * @return GNUNET_YES if we should continue to iterate,
765 regex_free_result (void *cls,
766 const struct GNUNET_HashCode * key,
776 * Cancel an ongoing regex search in the DHT and free all resources.
778 * @param ctx The search context.
781 regex_cancel_search (struct GNUNET_REGEX_search_handle *ctx)
783 GNUNET_free (ctx->description);
784 GNUNET_CONTAINER_multihashmap_iterate (ctx->dht_get_handles,
785 ®ex_cancel_dht_get, NULL);
786 GNUNET_CONTAINER_multihashmap_iterate (ctx->dht_get_results,
787 ®ex_free_result, NULL);
788 GNUNET_CONTAINER_multihashmap_destroy (ctx->dht_get_results);
789 GNUNET_CONTAINER_multihashmap_destroy (ctx->dht_get_handles);
790 if (0 < ctx->n_contexts)
794 for (i = 0; i < ctx->n_contexts; i++)
796 GNUNET_free (ctx->contexts[i]);
798 GNUNET_free (ctx->contexts);
803 GNUNET_REGEX_search_cancel (struct GNUNET_REGEX_search_handle *h)
805 regex_cancel_search (h);
811 /* end of regex_dht.c */