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19 * @author Bartlomiej Polot
20 * @file regex/regex_block_lib.c
21 * @brief functions for manipulating non-accept blocks stored for
25 #include "regex_block_lib.h"
26 #include "gnunet_constants.h"
28 #define LOG(kind,...) GNUNET_log_from (kind,"regex-bck",__VA_ARGS__)
30 GNUNET_NETWORK_STRUCT_BEGIN
33 * Information for each edge.
38 * Index of the destination of this edge in the
39 * unique destinations array.
41 uint16_t destination_index GNUNET_PACKED;
44 * Number of bytes the token for this edge takes in the
47 uint16_t token_length GNUNET_PACKED;
52 * @brief Block to announce a regex state.
58 * Length of the proof regex string.
60 uint16_t proof_len GNUNET_PACKED;
63 * Is this state an accepting state?
65 int16_t is_accepting GNUNET_PACKED;
68 * Number of edges parting from this state.
70 uint16_t num_edges GNUNET_PACKED;
73 * Nubmer of unique destinations reachable from this state.
75 uint16_t num_destinations GNUNET_PACKED;
77 /* followed by 'struct GNUNET_HashCode[num_destinations]' */
79 /* followed by 'struct EdgeInfo[edge_destination_indices]' */
81 /* followed by 'char proof[n_proof]', NOT 0-terminated */
83 /* followed by 'char tokens[num_edges][edge_info[k].token_length]';
84 essentially all of the tokens one after the other in the
85 order of the edges; tokens are NOT 0-terminated */
90 GNUNET_NETWORK_STRUCT_END
94 * Test if this block is marked as being an accept state.
96 * @param block block to test
97 * @param size number of bytes in block
98 * @return #GNUNET_YES if the block is accepting, #GNUNET_NO if not
101 GNUNET_BLOCK_is_accepting (const struct RegexBlock *block,
104 if (size < sizeof (struct RegexBlock))
107 return GNUNET_SYSERR;
109 return ntohs (block->is_accepting);
114 * Check if the given 'proof' matches the given 'key'.
116 * @param proof partial regex of a state
117 * @param proof_len number of bytes in 'proof'
118 * @param key hash of a state.
119 * @return #GNUNET_OK if the proof is valid for the given key.
122 REGEX_BLOCK_check_proof (const char *proof,
124 const struct GNUNET_HashCode *key)
126 struct GNUNET_HashCode key_check;
128 if ( (NULL == proof) || (NULL == key))
130 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Proof check failed, was NULL.\n");
133 GNUNET_CRYPTO_hash (proof, proof_len, &key_check);
135 GNUNET_CRYPTO_hash_cmp (key, &key_check)) ? GNUNET_OK : GNUNET_NO;
140 * Struct to keep track of the xquery while iterating all the edges in a block.
142 struct CheckEdgeContext
145 * Xquery: string we are looking for.
150 * Has any edge matched the xquery so far? (GNUNET_OK / GNUNET_NO)
158 * Iterator over all edges in a block, checking for a presence of a given query.
160 * @param cls Closure, (xquery context).
161 * @param token Token that follows to next state.
162 * @param len Lenght of token.
163 * @param key Hash of next state.
165 * @return #GNUNET_YES, to keep iterating
168 check_edge (void *cls,
171 const struct GNUNET_HashCode *key)
173 struct CheckEdgeContext *ctx = cls;
175 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
176 "edge %.*s [%u]: %s\n",
181 if (NULL == ctx->xquery)
183 if (strlen (ctx->xquery) < len)
184 return GNUNET_YES; /* too long */
185 if (0 == strncmp (ctx->xquery, token, len))
186 ctx->found = GNUNET_OK;
187 return GNUNET_YES; /* keep checking for malformed data! */
192 * Check if the regex block is well formed, including all edges.
194 * @param block The start of the block.
195 * @param size The size of the block.
196 * @param query the query for the block
197 * @param xquery String describing the edge we are looking for.
198 * Can be NULL in case this is a put block.
199 * @return #GNUNET_OK in case it's fine.
200 * #GNUNET_NO in case the xquery exists and is not found (IRRELEVANT).
201 * #GNUNET_SYSERR if the block is invalid.
204 REGEX_BLOCK_check (const struct RegexBlock *block,
206 const struct GNUNET_HashCode *query,
209 struct GNUNET_HashCode key;
210 struct CheckEdgeContext ctx;
213 LOG (GNUNET_ERROR_TYPE_DEBUG,
216 REGEX_BLOCK_get_key (block, size,
220 return GNUNET_SYSERR;
225 sizeof (struct GNUNET_HashCode)))
228 return GNUNET_SYSERR;
230 if ( (GNUNET_YES == ntohs (block->is_accepting)) &&
231 ( (NULL == xquery) || ('\0' == xquery[0]) ) )
233 LOG (GNUNET_ERROR_TYPE_DEBUG,
234 " out! Is accepting: %u, xquery %p\n",
235 ntohs(block->is_accepting),
240 ctx.found = GNUNET_NO;
241 res = REGEX_BLOCK_iterate (block, size, &check_edge, &ctx);
242 if (GNUNET_SYSERR == res)
243 return GNUNET_SYSERR;
246 LOG (GNUNET_ERROR_TYPE_DEBUG, "Result %d\n", ctx.found);
252 * Obtain the key that a particular block is to be stored under.
254 * @param block block to get the key from
255 * @param block_len number of bytes in block
256 * @param key where to store the key
257 * @return #GNUNET_OK on success, #GNUNET_SYSERR if the block is malformed
260 REGEX_BLOCK_get_key (const struct RegexBlock *block,
262 struct GNUNET_HashCode *key)
265 const struct GNUNET_HashCode *destinations;
266 const struct EdgeInfo *edges;
267 uint16_t num_destinations;
271 if (block_len < sizeof (struct RegexBlock))
274 return GNUNET_SYSERR;
276 num_destinations = ntohs (block->num_destinations);
277 num_edges = ntohs (block->num_edges);
278 len = ntohs (block->proof_len);
279 destinations = (const struct GNUNET_HashCode *) &block[1];
280 edges = (const struct EdgeInfo *) &destinations[num_destinations];
281 total = sizeof (struct RegexBlock) + num_destinations * sizeof (struct GNUNET_HashCode) + num_edges * sizeof (struct EdgeInfo) + len;
282 if (block_len < total)
285 return GNUNET_SYSERR;
287 GNUNET_CRYPTO_hash (&edges[num_edges], len, key);
293 * Iterate over all edges of a block of a regex state.
295 * @param block Block to iterate over.
296 * @param size Size of @a block.
297 * @param iterator Function to call on each edge in the block.
298 * @param iter_cls Closure for the @a iterator.
299 * @return #GNUNET_SYSERR if an error has been encountered.
300 * #GNUNET_OK if no error has been encountered.
301 * Note that if the iterator stops the iteration by returning
302 * #GNUNET_NO, the block will no longer be checked for further errors.
303 * The return value will be GNUNET_OK meaning that no errors were
304 * found until the edge last notified to the iterator, but there might
305 * be errors in further edges.
308 REGEX_BLOCK_iterate (const struct RegexBlock *block,
310 REGEX_INTERNAL_EgdeIterator iterator,
314 const struct GNUNET_HashCode *destinations;
315 const struct EdgeInfo *edges;
317 uint16_t num_destinations;
323 LOG (GNUNET_ERROR_TYPE_DEBUG, "Block iterate\n");
324 if (size < sizeof (struct RegexBlock))
327 return GNUNET_SYSERR;
329 num_destinations = ntohs (block->num_destinations);
330 num_edges = ntohs (block->num_edges);
331 len = ntohs (block->proof_len);
332 destinations = (const struct GNUNET_HashCode *) &block[1];
333 edges = (const struct EdgeInfo *) &destinations[num_destinations];
334 aux = (const char *) &edges[num_edges];
335 total = sizeof (struct RegexBlock) + num_destinations * sizeof (struct GNUNET_HashCode) + num_edges * sizeof (struct EdgeInfo) + len;
339 return GNUNET_SYSERR;
341 for (n=0;n<num_edges;n++)
342 total += ntohs (edges[n].token_length);
345 fprintf (stderr, "Expected %u, got %u\n",
347 (unsigned int) total);
349 return GNUNET_SYSERR;
352 LOG (GNUNET_ERROR_TYPE_DEBUG,
353 "Start iterating block of size %u, proof %u, off %u edges %u\n",
355 /* &aux[off] always points to our token */
356 for (n=0;n<num_edges;n++)
358 LOG (GNUNET_ERROR_TYPE_DEBUG,
359 "Edge %u/%u, off %u tokenlen %u (%.*s)\n",
361 ntohs (edges[n].token_length), ntohs (edges[n].token_length),
363 if (NULL != iterator)
364 if (GNUNET_NO == iterator (iter_cls,
366 ntohs (edges[n].token_length),
367 &destinations[ntohs (edges[n].destination_index)]))
369 off += ntohs (edges[n].token_length);
376 * Construct a regex block to be stored in the DHT.
378 * @param proof proof string for the block
379 * @param num_edges number of edges in the block
380 * @param edges the edges of the block
381 * @param accepting is this an accepting state
382 * @param rsize set to the size of the returned block (OUT-only)
383 * @return the regex block, NULL on error
386 REGEX_BLOCK_create (const char *proof,
387 unsigned int num_edges,
388 const struct REGEX_BLOCK_Edge *edges,
392 struct RegexBlock *block;
393 struct GNUNET_HashCode destinations[1024]; /* 1024 = 64k/64 bytes/key == absolute MAX */
394 uint16_t destination_indices[num_edges];
395 struct GNUNET_HashCode *dests;
396 struct EdgeInfo *edgeinfos;
401 unsigned int unique_destinations;
406 len = strlen (proof);
407 if (len > UINT16_MAX)
412 unique_destinations = 0;
413 total = sizeof (struct RegexBlock) + len;
414 for (i=0;i<num_edges;i++)
416 slen = strlen (edges[i].label);
417 if (slen > UINT16_MAX)
423 for (j=0;j<unique_destinations;j++)
424 if (0 == memcmp (&destinations[j],
425 &edges[i].destination,
426 sizeof (struct GNUNET_HashCode)))
433 destination_indices[i] = j;
434 if (j == unique_destinations)
435 destinations[unique_destinations++] = edges[i].destination;
437 total += num_edges * sizeof (struct EdgeInfo) + unique_destinations * sizeof (struct GNUNET_HashCode);
438 if (total >= GNUNET_CONSTANTS_MAX_BLOCK_SIZE)
443 block = GNUNET_malloc (total);
444 block->proof_len = htons (len);
445 block->is_accepting = htons (accepting);
446 block->num_edges = htons (num_edges);
447 block->num_destinations = htons (unique_destinations);
448 dests = (struct GNUNET_HashCode *) &block[1];
449 GNUNET_memcpy (dests, destinations, sizeof (struct GNUNET_HashCode) * unique_destinations);
450 edgeinfos = (struct EdgeInfo *) &dests[unique_destinations];
451 aux = (char *) &edgeinfos[num_edges];
453 GNUNET_memcpy (aux, proof, len);
454 for (i=0;i<num_edges;i++)
456 slen = strlen (edges[i].label);
457 edgeinfos[i].token_length = htons ((uint16_t) slen);
458 edgeinfos[i].destination_index = htons (destination_indices[i]);
459 GNUNET_memcpy (&aux[off],
469 /* end of regex_block_lib.c */