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21 * @author Bartlomiej Polot
22 * @file regex/regex_block_lib.c
23 * @brief functions for manipulating non-accept blocks stored for
27 #include "regex_block_lib.h"
29 #define LOG(kind,...) GNUNET_log_from (kind,"regex-bck",__VA_ARGS__)
32 * Struct to keep track of the xquery while iterating all the edges in a block.
34 struct regex_block_xquery_ctx
37 * Xquery: string we are looking for.
42 * Has any edge matched the xquery so far? (GNUNET_OK / GNUNET_NO)
47 * Key of the block we are iterating (for debug purposes).
54 * Iterator over all edges in a block, checking for a presence of a given query.
56 * @param cls Closure, (xquery context).
57 * @param token Token that follows to next state.
58 * @param len Lenght of token.
59 * @param key Hash of next state.
61 * @return GNUNET_YES, to keep iterating
64 check_edge (void *cls,
67 const struct GNUNET_HashCode *key)
69 struct regex_block_xquery_ctx *ctx = cls;
71 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
72 "edge %.*s [%u]: %s->%s\n",
73 (int) len, token, len, ctx->key, GNUNET_h2s(key));
74 if (NULL == ctx->xquery)
76 if (strlen (ctx->xquery) < len)
77 return GNUNET_YES; /* too long */
78 if (0 == strncmp (ctx->xquery, token, len))
79 ctx->found = GNUNET_OK;
80 return GNUNET_YES; /* keep checking for malformed data! */
85 * Check if the regex block is well formed, including all edges.
87 * @param block The start of the block.
88 * @param size The size of the block.
89 * @param xquery String describing the edge we are looking for.
90 * Can be NULL in case this is a put block.
92 * @return GNUNET_OK in case it's fine.
93 * GNUNET_NO in case the xquery exists and is not found (IRRELEVANT).
94 * GNUNET_SYSERR if the block is invalid.
97 REGEX_BLOCK_check (const struct RegexBlock *block,
102 struct regex_block_xquery_ctx ctx;
104 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
105 "Checking block with xquery `%s'\n",
106 NULL != xquery ? xquery : "NULL");
107 if ( (GNUNET_YES == ntohl (block->accepting)) &&
108 ( (NULL == xquery) || ('\0' == xquery[0]) ) )
111 ctx.found = GNUNET_NO;
112 ctx.key = GNUNET_strdup (GNUNET_h2s (&block->key));
113 res = REGEX_BLOCK_iterate (block, size, &check_edge, &ctx);
114 GNUNET_free (ctx.key);
115 if (GNUNET_SYSERR == res)
116 return GNUNET_SYSERR;
124 * Iterate over all edges of a block of a regex state.
126 * @param block Block to iterate over.
127 * @param size Size of block.
128 * @param iterator Function to call on each edge in the block.
129 * @param iter_cls Closure for the iterator.
131 * @return GNUNET_SYSERR if an error has been encountered.
132 * GNUNET_OK if no error has been encountered.
133 * Note that if the iterator stops the iteration by returning
134 * GNUNET_NO, the block will no longer be checked for further errors.
135 * The return value will be GNUNET_OK meaning that no errors were
136 * found until the edge last notified to the iterator, but there might
137 * be errors in further edges.
140 REGEX_BLOCK_iterate (const struct RegexBlock *block,
142 REGEX_INTERNAL_EgdeIterator iterator,
145 struct RegexEdge *edge;
147 unsigned int n_token;
152 offset = sizeof (struct RegexBlock);
153 if (offset >= size) /* Is it safe to access the regex block? */
156 return GNUNET_SYSERR;
158 n = ntohl (block->n_proof);
160 if (offset >= size) /* Is it safe to access the regex proof? */
163 return GNUNET_SYSERR;
165 aux = (char *) &block[1]; /* Skip regex block */
166 aux = &aux[n]; /* Skip regex proof */
167 n = ntohl (block->n_edges);
168 LOG (GNUNET_ERROR_TYPE_DEBUG,
169 "Start iterating block of size %u, proof %u, off %u edges %u\n",
170 size, ntohl (block->n_proof), offset, n);
171 /* aux always points at the end of the previous block */
172 for (i = 0; i < n; i++)
174 offset += sizeof (struct RegexEdge);
175 LOG (GNUNET_ERROR_TYPE_DEBUG, "* Edge %u, off %u\n", i, offset);
176 if (offset >= size) /* Is it safe to access the next edge block? */
178 LOG (GNUNET_ERROR_TYPE_WARNING,
179 "* Size not enough for RegexEdge, END\n");
181 return GNUNET_SYSERR;
183 edge = (struct RegexEdge *) aux;
184 n_token = ntohl (edge->n_token);
186 LOG (GNUNET_ERROR_TYPE_DEBUG,
187 "* Token length %u, off %u\n", n_token, offset);
188 if (offset > size) /* Is it safe to access the edge token? */
190 LOG (GNUNET_ERROR_TYPE_WARNING,
191 "* Size not enough for edge token, END\n");
193 return GNUNET_SYSERR;
195 aux = (char *) &edge[1]; /* Skip edge block */
196 if (NULL != iterator)
197 if (GNUNET_NO == iterator (iter_cls, aux, n_token, &edge->key))
199 aux = &aux[n_token]; /* Skip edge token */
201 /* The total size should be exactly the size of (regex + all edges) blocks
202 * If size == -1, block is from cache and therefore previously checked and
203 * assumed correct. */
204 if ( (offset != size) && (SIZE_MAX != size) )
207 return GNUNET_SYSERR;
214 * Construct a regex block to be stored in the DHT.
216 * @param proof proof string for the block
217 * @param num_edges number of edges in the block
218 * @param edges the edges of the block
219 * @return the regex block
222 REGEX_BLOCK_create (const struct GNUNET_HashCode *key,
224 unsigned int num_edges,
225 const struct REGEX_BLOCK_Edge *edges,
229 struct RegexBlock *block;
230 struct RegexEdge *block_edge;
238 size = sizeof (struct RegexBlock) + len;
239 block = GNUNET_malloc (size);
241 block->n_proof = htonl (len);
242 block->n_edges = htonl (num_edges);
243 block->accepting = htonl (accepting);
245 /* Store the proof at the end of the block. */
246 aux = (char *) &block[1];
247 memcpy (aux, proof, len);
250 /* Store each edge in a variable length MeshEdge struct at the
251 * very end of the MeshRegexBlock structure.
253 for (i = 0; i < num_edges; i++)
255 /* aux points at the end of the last block */
256 len = strlen (edges[i].label);
257 size += sizeof (struct RegexEdge) + len;
258 // Calculate offset FIXME is this ok? use size instead?
259 offset = aux - (char *) block;
260 block = GNUNET_realloc (block, size);
261 aux = &((char *) block)[offset];
262 block_edge = (struct RegexEdge *) aux;
263 block_edge->key = edges[i].destination;
264 block_edge->n_token = htonl (len);
265 aux = (char *) &block_edge[1];
266 memcpy (aux, edges[i].label, len);
274 /* end of regex_block_lib.c */