/*
This file is part of GNUnet.
- (C) 2012,2013 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2012,2013 GNUnet e.V.
- GNUnet is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published
- by the Free Software Foundation; either version 3, or (at your
- option) any later version.
+ GNUnet is free software: you can redistribute it and/or modify it
+ under the terms of the GNU Affero General Public License as published
+ by the Free Software Foundation, either version 3 of the License,
+ or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
+ Affero General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
-*/
+ You should have received a copy of the GNU Affero General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+ SPDX-License-Identifier: AGPL3.0-or-later
+ */
/**
* @author Bartlomiej Polot
* @file regex/regex_block_lib.c
+ * @brief functions for manipulating non-accept blocks stored for
+ * regex in the DHT
*/
#include "platform.h"
#include "regex_block_lib.h"
+#include "gnunet_constants.h"
-#define LOG(kind,...) GNUNET_log_from (kind,"regex-bck",__VA_ARGS__)
+#define LOG(kind, ...) GNUNET_log_from(kind, "regex-bck", __VA_ARGS__)
+
+GNUNET_NETWORK_STRUCT_BEGIN
/**
- * Struct to keep track of the xquery while iterating all the edges in a block.
+ * Information for each edge.
+ */
+struct EdgeInfo {
+ /**
+ * Index of the destination of this edge in the
+ * unique destinations array.
+ */
+ uint16_t destination_index GNUNET_PACKED;
+
+ /**
+ * Number of bytes the token for this edge takes in the
+ * token area.
+ */
+ uint16_t token_length GNUNET_PACKED;
+};
+
+
+/**
+ * @brief Block to announce a regex state.
+ */
+struct RegexBlock {
+ /**
+ * Length of the proof regex string.
+ */
+ uint16_t proof_len GNUNET_PACKED;
+
+ /**
+ * Is this state an accepting state?
+ */
+ int16_t is_accepting GNUNET_PACKED;
+
+ /**
+ * Number of edges parting from this state.
+ */
+ uint16_t num_edges GNUNET_PACKED;
+
+ /**
+ * Nubmer of unique destinations reachable from this state.
+ */
+ uint16_t num_destinations GNUNET_PACKED;
+
+ /* followed by 'struct GNUNET_HashCode[num_destinations]' */
+
+ /* followed by 'struct EdgeInfo[edge_destination_indices]' */
+
+ /* followed by 'char proof[n_proof]', NOT 0-terminated */
+
+ /* followed by 'char tokens[num_edges][edge_info[k].token_length]';
+ essentially all of the tokens one after the other in the
+ order of the edges; tokens are NOT 0-terminated */
+};
+
+
+GNUNET_NETWORK_STRUCT_END
+
+
+/**
+ * Test if this block is marked as being an accept state.
+ *
+ * @param block block to test
+ * @param size number of bytes in block
+ * @return #GNUNET_YES if the block is accepting, #GNUNET_NO if not
+ */
+int
+GNUNET_BLOCK_is_accepting(const struct RegexBlock *block,
+ size_t size)
+{
+ if (size < sizeof(struct RegexBlock))
+ {
+ GNUNET_break_op(0);
+ return GNUNET_SYSERR;
+ }
+ return ntohs(block->is_accepting);
+}
+
+
+/**
+ * Check if the given 'proof' matches the given 'key'.
+ *
+ * @param proof partial regex of a state
+ * @param proof_len number of bytes in 'proof'
+ * @param key hash of a state.
+ * @return #GNUNET_OK if the proof is valid for the given key.
*/
-struct regex_block_xquery_ctx
+int
+REGEX_BLOCK_check_proof(const char *proof,
+ size_t proof_len,
+ const struct GNUNET_HashCode *key)
{
+ struct GNUNET_HashCode key_check;
+
+ if ((NULL == proof) || (NULL == key))
+ {
+ GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Proof check failed, was NULL.\n");
+ return GNUNET_NO;
+ }
+ GNUNET_CRYPTO_hash(proof, proof_len, &key_check);
+ return (0 ==
+ GNUNET_CRYPTO_hash_cmp(key, &key_check)) ? GNUNET_OK : GNUNET_NO;
+}
+
+
+/**
+ * Struct to keep track of the xquery while iterating all the edges in a block.
+ */
+struct CheckEdgeContext {
/**
* Xquery: string we are looking for.
*/
* @param token Token that follows to next state.
* @param len Lenght of token.
* @param key Hash of next state.
- *
- * @return GNUNET_YES, to keep iterating
+ *
+ * @return #GNUNET_YES, to keep iterating
*/
static int
-check_edge (void *cls,
- const char *token,
- size_t len,
- const struct GNUNET_HashCode *key)
+check_edge(void *cls,
+ const char *token,
+ size_t len,
+ const struct GNUNET_HashCode *key)
{
- struct regex_block_xquery_ctx *ctx = cls;
+ struct CheckEdgeContext *ctx = cls;
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, " edge %.*s [%u]\n",
- (int) len, token, len);
+ GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
+ "edge %.*s [%u]: %s\n",
+ (int)len,
+ token,
+ (unsigned int)len,
+ GNUNET_h2s(key));
if (NULL == ctx->xquery)
return GNUNET_YES;
- if (strlen (ctx->xquery) < len)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, " too long!\n");
- return GNUNET_YES;
- }
- if (0 == strncmp (ctx->xquery, token, len))
- {
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, " OK!\n");
+ if (strlen(ctx->xquery) < len)
+ return GNUNET_YES; /* too long */
+ if (0 == strncmp(ctx->xquery, token, len))
ctx->found = GNUNET_OK;
- }
- else
- {
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, " KO!\n");
- }
-
return GNUNET_YES; /* keep checking for malformed data! */
}
+/**
+ * Check if the regex block is well formed, including all edges.
+ *
+ * @param block The start of the block.
+ * @param size The size of the block.
+ * @param query the query for the block
+ * @param xquery String describing the edge we are looking for.
+ * Can be NULL in case this is a put block.
+ * @return #GNUNET_OK in case it's fine.
+ * #GNUNET_NO in case the xquery exists and is not found (IRRELEVANT).
+ * #GNUNET_SYSERR if the block is invalid.
+ */
int
-GNUNET_REGEX_block_check (const struct RegexBlock *block,
- size_t size,
- const char *xquery)
+REGEX_BLOCK_check(const struct RegexBlock *block,
+ size_t size,
+ const struct GNUNET_HashCode *query,
+ const char *xquery)
{
+ struct GNUNET_HashCode key;
+ struct CheckEdgeContext ctx;
int res;
- struct regex_block_xquery_ctx ctx;
-
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "* Checking block with xquery \"%s\"\n",
- NULL != xquery ? xquery : "NULL");
- if ( (GNUNET_YES == ntohl (block->accepting)) &&
- ( (NULL == xquery) || ('\0' == xquery[0]) )
- )
- return GNUNET_OK;
+
+ LOG(GNUNET_ERROR_TYPE_DEBUG,
+ "Block check\n");
+ if (GNUNET_OK !=
+ REGEX_BLOCK_get_key(block, size,
+ &key))
+ {
+ GNUNET_break_op(0);
+ return GNUNET_SYSERR;
+ }
+ if (NULL != query &&
+ 0 != GNUNET_memcmp(&key,
+ query))
+ {
+ GNUNET_break_op(0);
+ return GNUNET_SYSERR;
+ }
+ if ((GNUNET_YES == ntohs(block->is_accepting)) &&
+ ((NULL == xquery) || ('\0' == xquery[0])))
+ {
+ LOG(GNUNET_ERROR_TYPE_DEBUG,
+ " out! Is accepting: %u, xquery %p\n",
+ ntohs(block->is_accepting),
+ xquery);
+ return GNUNET_OK;
+ }
ctx.xquery = xquery;
ctx.found = GNUNET_NO;
- res = GNUNET_REGEX_block_iterate (block, size, &check_edge, &ctx);
+ res = REGEX_BLOCK_iterate(block, size, &check_edge, &ctx);
if (GNUNET_SYSERR == res)
return GNUNET_SYSERR;
if (NULL == xquery)
return GNUNET_YES;
+ LOG(GNUNET_ERROR_TYPE_DEBUG, "Result %d\n", ctx.found);
return ctx.found;
}
+/**
+ * Obtain the key that a particular block is to be stored under.
+ *
+ * @param block block to get the key from
+ * @param block_len number of bytes in block
+ * @param key where to store the key
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if the block is malformed
+ */
int
-GNUNET_REGEX_block_iterate (const struct RegexBlock *block,
- size_t size,
- GNUNET_REGEX_EgdeIterator iterator,
- void *iter_cls)
+REGEX_BLOCK_get_key(const struct RegexBlock *block,
+ size_t block_len,
+ struct GNUNET_HashCode *key)
{
- struct RegexEdge *edge;
+ uint16_t len;
+ const struct GNUNET_HashCode *destinations;
+ const struct EdgeInfo *edges;
+ uint16_t num_destinations;
+ uint16_t num_edges;
+ size_t total;
+
+ if (block_len < sizeof(struct RegexBlock))
+ {
+ GNUNET_break_op(0);
+ return GNUNET_SYSERR;
+ }
+ num_destinations = ntohs(block->num_destinations);
+ num_edges = ntohs(block->num_edges);
+ len = ntohs(block->proof_len);
+ destinations = (const struct GNUNET_HashCode *)&block[1];
+ edges = (const struct EdgeInfo *)&destinations[num_destinations];
+ total = sizeof(struct RegexBlock) + num_destinations * sizeof(struct GNUNET_HashCode) + num_edges * sizeof(struct EdgeInfo) + len;
+ if (block_len < total)
+ {
+ GNUNET_break_op(0);
+ return GNUNET_SYSERR;
+ }
+ GNUNET_CRYPTO_hash(&edges[num_edges], len, key);
+ return GNUNET_OK;
+}
+
+
+/**
+ * Iterate over all edges of a block of a regex state.
+ *
+ * @param block Block to iterate over.
+ * @param size Size of @a block.
+ * @param iterator Function to call on each edge in the block.
+ * @param iter_cls Closure for the @a iterator.
+ * @return #GNUNET_SYSERR if an error has been encountered.
+ * #GNUNET_OK if no error has been encountered.
+ * Note that if the iterator stops the iteration by returning
+ * #GNUNET_NO, the block will no longer be checked for further errors.
+ * The return value will be GNUNET_OK meaning that no errors were
+ * found until the edge last notified to the iterator, but there might
+ * be errors in further edges.
+ */
+int
+REGEX_BLOCK_iterate(const struct RegexBlock *block,
+ size_t size,
+ REGEX_INTERNAL_EgdeIterator iterator,
+ void *iter_cls)
+{
+ uint16_t len;
+ const struct GNUNET_HashCode *destinations;
+ const struct EdgeInfo *edges;
+ const char *aux;
+ uint16_t num_destinations;
+ uint16_t num_edges;
+ size_t total;
unsigned int n;
- unsigned int n_token;
- unsigned int i;
- size_t offset;
- char *aux;
+ size_t off;
- offset = sizeof (struct RegexBlock);
- LOG (GNUNET_ERROR_TYPE_DEBUG,
- "* Start iterating block of size %u, off %u\n",
- size, offset);
- if (offset >= size) /* Is it safe to access the regex block? */
- {
- LOG (GNUNET_ERROR_TYPE_WARNING,
- "* Block is smaller than struct RegexBlock, END\n");
- GNUNET_break_op (0);
- return GNUNET_SYSERR;
- }
- n = ntohl (block->n_proof);
- offset += n;
- LOG (GNUNET_ERROR_TYPE_DEBUG,
- "* Proof length: %u, off %u\n", n, offset);
- if (offset >= size) /* Is it safe to access the regex proof? */
- {
- LOG (GNUNET_ERROR_TYPE_WARNING,
- "* Block is smaller than Block + proof, END\n");
- GNUNET_break_op (0);
- return GNUNET_SYSERR;
- }
- aux = (char *) &block[1]; /* Skip regex block */
- aux = &aux[n]; /* Skip regex proof */
- n = ntohl (block->n_edges);
- LOG (GNUNET_ERROR_TYPE_DEBUG, "* Edges: %u\n", n);
- /* aux always points at the end of the previous block */
- for (i = 0; i < n; i++)
- {
- offset += sizeof (struct RegexEdge);
- LOG (GNUNET_ERROR_TYPE_DEBUG, "* Edge %u, off %u\n", i, offset);
- if (offset >= size) /* Is it safe to access the next edge block? */
+ LOG(GNUNET_ERROR_TYPE_DEBUG, "Block iterate\n");
+ if (size < sizeof(struct RegexBlock))
+ {
+ GNUNET_break_op(0);
+ return GNUNET_SYSERR;
+ }
+ num_destinations = ntohs(block->num_destinations);
+ num_edges = ntohs(block->num_edges);
+ len = ntohs(block->proof_len);
+ destinations = (const struct GNUNET_HashCode *)&block[1];
+ edges = (const struct EdgeInfo *)&destinations[num_destinations];
+ aux = (const char *)&edges[num_edges];
+ total = sizeof(struct RegexBlock) + num_destinations * sizeof(struct GNUNET_HashCode) + num_edges * sizeof(struct EdgeInfo) + len;
+ if (size < total)
{
- LOG (GNUNET_ERROR_TYPE_WARNING,
- "* Size not enough for RegexEdge, END\n");
- GNUNET_break_op (0);
+ GNUNET_break_op(0);
return GNUNET_SYSERR;
}
- edge = (struct RegexEdge *) aux;
- n_token = ntohl (edge->n_token);
- offset += n_token;
- LOG (GNUNET_ERROR_TYPE_DEBUG,
- "* Token length %u, off %u\n", n_token, offset);
- if (offset > size) /* Is it safe to access the edge token? */
+ for (n = 0; n < num_edges; n++)
+ total += ntohs(edges[n].token_length);
+ if (size != total)
{
- LOG (GNUNET_ERROR_TYPE_WARNING,
- "* Size not enough for edge token, END\n");
- GNUNET_break_op (0);
+ fprintf(stderr, "Expected %u, got %u\n",
+ (unsigned int)size,
+ (unsigned int)total);
+ GNUNET_break_op(0);
return GNUNET_SYSERR;
}
- aux = (char *) &edge[1]; /* Skip edge block */
- if (NULL != iterator)
- if (GNUNET_NO == iterator (iter_cls, aux, n_token, &edge->key))
- return GNUNET_OK;
- aux = &aux[n_token]; /* Skip edge token */
- }
- /* The total size should be exactly the size of (regex + all edges) blocks
- * If size == -1, block is from cache and therefore previously checked and
- * assumed correct. */
- if (offset == size || SIZE_MAX == size)
- {
- LOG (GNUNET_ERROR_TYPE_DEBUG, "* Block processed, END OK\n");
- return GNUNET_OK;
- }
- LOG (GNUNET_ERROR_TYPE_WARNING,
- "* Size %u (%d), read %u END KO\n", size, size, offset);
- GNUNET_break_op (0);
- return GNUNET_SYSERR;
+ off = len;
+ LOG(GNUNET_ERROR_TYPE_DEBUG,
+ "Start iterating block of size %u, proof %u, off %u edges %u\n",
+ size, len, off, n);
+ /* &aux[off] always points to our token */
+ for (n = 0; n < num_edges; n++)
+ {
+ LOG(GNUNET_ERROR_TYPE_DEBUG,
+ "Edge %u/%u, off %u tokenlen %u (%.*s)\n",
+ n + 1, num_edges, off,
+ ntohs(edges[n].token_length), ntohs(edges[n].token_length),
+ &aux[off]);
+ if (NULL != iterator)
+ if (GNUNET_NO == iterator(iter_cls,
+ &aux[off],
+ ntohs(edges[n].token_length),
+ &destinations[ntohs(edges[n].destination_index)]))
+ return GNUNET_OK;
+ off += ntohs(edges[n].token_length);
+ }
+ return GNUNET_OK;
}
+
+/**
+ * Construct a regex block to be stored in the DHT.
+ *
+ * @param proof proof string for the block
+ * @param num_edges number of edges in the block
+ * @param edges the edges of the block
+ * @param accepting is this an accepting state
+ * @param rsize set to the size of the returned block (OUT-only)
+ * @return the regex block, NULL on error
+ */
+struct RegexBlock *
+REGEX_BLOCK_create(const char *proof,
+ unsigned int num_edges,
+ const struct REGEX_BLOCK_Edge *edges,
+ int accepting,
+ size_t *rsize)
+{
+ struct RegexBlock *block;
+ struct GNUNET_HashCode destinations[1024]; /* 1024 = 64k/64 bytes/key == absolute MAX */
+ uint16_t destination_indices[num_edges];
+ struct GNUNET_HashCode *dests;
+ struct EdgeInfo *edgeinfos;
+ size_t off;
+ size_t len;
+ size_t total;
+ size_t slen;
+ unsigned int unique_destinations;
+ unsigned int j;
+ unsigned int i;
+ char *aux;
+
+ len = strlen(proof);
+ if (len > UINT16_MAX)
+ {
+ GNUNET_break(0);
+ return NULL;
+ }
+ unique_destinations = 0;
+ total = sizeof(struct RegexBlock) + len;
+ for (i = 0; i < num_edges; i++)
+ {
+ slen = strlen(edges[i].label);
+ if (slen > UINT16_MAX)
+ {
+ GNUNET_break(0);
+ return NULL;
+ }
+ total += slen;
+ for (j = 0; j < unique_destinations; j++)
+ if (0 == memcmp(&destinations[j],
+ &edges[i].destination,
+ sizeof(struct GNUNET_HashCode)))
+ break;
+ if (j >= 1024)
+ {
+ GNUNET_break(0);
+ return NULL;
+ }
+ destination_indices[i] = j;
+ if (j == unique_destinations)
+ destinations[unique_destinations++] = edges[i].destination;
+ }
+ total += num_edges * sizeof(struct EdgeInfo) + unique_destinations * sizeof(struct GNUNET_HashCode);
+ if (total >= GNUNET_CONSTANTS_MAX_BLOCK_SIZE)
+ {
+ GNUNET_break(0);
+ return NULL;
+ }
+ block = GNUNET_malloc(total);
+ block->proof_len = htons(len);
+ block->is_accepting = htons(accepting);
+ block->num_edges = htons(num_edges);
+ block->num_destinations = htons(unique_destinations);
+ dests = (struct GNUNET_HashCode *)&block[1];
+ GNUNET_memcpy(dests, destinations, sizeof(struct GNUNET_HashCode) * unique_destinations);
+ edgeinfos = (struct EdgeInfo *)&dests[unique_destinations];
+ aux = (char *)&edgeinfos[num_edges];
+ off = len;
+ GNUNET_memcpy(aux, proof, len);
+ for (i = 0; i < num_edges; i++)
+ {
+ slen = strlen(edges[i].label);
+ edgeinfos[i].token_length = htons((uint16_t)slen);
+ edgeinfos[i].destination_index = htons(destination_indices[i]);
+ GNUNET_memcpy(&aux[off],
+ edges[i].label,
+ slen);
+ off += slen;
+ }
+ *rsize = total;
+ return block;
+}
+
+
/* end of regex_block_lib.c */
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