continuing refactoring of regex library structure, disambiguating symbol names between old regex library which is now internal and the public API; moving IP-to-regex conversion functions to tun library, as only vpn is using those to begin with

1 files changed, 320 insertions, 0 deletions

diff --git a/src/regex/regex_internal_lib.h b/src/regex/regex_internal_lib.h
new file mode 100644
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--- /dev/null
+++ b/src/regex/regex_internal_lib.h
@@ -0,0 +1,320 @@
+/*
+     This file is part of GNUnet
+     (C) 2012, 2013 Christian Grothoff (and other contributing authors)
+
+     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 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.
+
+     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.
+*/
+/**
+ * @file regex/regex_internal_lib.h
+ * @brief library to parse regular expressions into dfa
+ * @author Maximilian Szengel
+ *
+ */
+
+#ifndef REGEX_INTERNAL_LIB_H
+#define REGEX_INTERNAL_LIB_H
+
+#include "gnunet_util_lib.h"
+#include "gnunet_dht_service.h"
+#include "gnunet_statistics_service.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#if 0                           /* keep Emacsens' auto-indent happy */
+}
+#endif
+#endif
+
+
+
+
+/**
+ * Automaton (NFA/DFA) representation.
+- */
+struct REGEX_ITERNAL_Automaton;
+
+
+/**
+ * Edge representation.
+ */
+struct REGEX_ITERNAL_Edge
+{
+  /**
+   * Label of the edge.  FIXME: might want to not consume exactly multiples of 8 bits, need length?
+   */
+  const char *label;
+
+  /**
+   * Destionation of the edge.
+   */
+  struct GNUNET_HashCode destination;
+};
+
+
+/**
+ * Construct DFA for the given 'regex' of length 'len'.
+ *
+ * Path compression means, that for example a DFA o -> a -> b -> c -> o will be
+ * compressed to o -> abc -> o. Note that this parameter influences the
+ * non-determinism of states of the resulting NFA in the DHT (number of outgoing
+ * edges with the same label). For example for an application that stores IPv4
+ * addresses as bitstrings it could make sense to limit the path compression to
+ * 4 or 8.
+ *
+ * @param regex regular expression string.
+ * @param len length of the regular expression.
+ * @param max_path_len limit the path compression length to the
+ *        given value. If set to 1, no path compression is applied. Set to 0 for
+ *        maximal possible path compression (generally not desireable).
+ * @return DFA, needs to be freed using REGEX_ITERNAL_automaton_destroy.
+ */
+struct REGEX_ITERNAL_Automaton *
+REGEX_ITERNAL_construct_dfa (const char *regex, const size_t len,
+                            unsigned int max_path_len);
+
+
+/**
+ * Free the memory allocated by constructing the REGEX_ITERNAL_Automaton.
+ * data structure.
+ *
+ * @param a automaton to be destroyed.
+ */
+void
+REGEX_ITERNAL_automaton_destroy (struct REGEX_ITERNAL_Automaton *a);
+
+
+/**
+ * Options for graph creation function
+ * REGEX_ITERNAL_automaton_save_graph.
+ */
+enum REGEX_ITERNAL_GraphSavingOptions
+{
+  /**
+   * Default. Do nothing special.
+   */
+  REGEX_ITERNAL_GRAPH_DEFAULT = 0,
+
+  /**
+   * The generated graph will include extra information such as the NFA states
+   * that were used to generate the DFA state.
+   */
+  REGEX_ITERNAL_GRAPH_VERBOSE = 1,
+
+  /**
+   * Enable graph coloring. Will color each SCC in a different color.
+   */
+  REGEX_ITERNAL_GRAPH_COLORING = 2
+};
+
+
+/**
+ * Save the given automaton as a GraphViz dot file.
+ *
+ * @param a the automaton to be saved.
+ * @param filename where to save the file.
+ * @param options options for graph generation that include coloring or verbose
+ *                mode
+ */
+void
+REGEX_ITERNAL_automaton_save_graph (struct REGEX_ITERNAL_Automaton *a,
+                                   const char *filename,
+                                   enum REGEX_ITERNAL_GraphSavingOptions options);
+
+
+/**
+ * Evaluates the given 'string' against the given compiled regex.
+ *
+ * @param a automaton.
+ * @param string string to check.
+ *
+ * @return 0 if string matches, non 0 otherwise.
+ */
+int
+REGEX_ITERNAL_eval (struct REGEX_ITERNAL_Automaton *a,
+                   const char *string);
+
+
+/**
+ * Get the first key for the given 'input_string'. This hashes
+ * the first x bits of the 'input_string'.
+ *
+ * @param input_string string.
+ * @param string_len length of the 'input_string'.
+ * @param key pointer to where to write the hash code.
+ *
+ * @return number of bits of 'input_string' that have been consumed
+ *         to construct the key
+ */
+size_t
+REGEX_ITERNAL_get_first_key (const char *input_string, size_t string_len,
+                            struct GNUNET_HashCode * key);
+
+
+/**
+ * Check if the given 'proof' matches the given 'key'.
+ *
+ * @param proof partial regex of a state.
+ * @param key hash of a state.
+ *
+ * @return GNUNET_OK if the proof is valid for the given key.
+ */
+int
+REGEX_ITERNAL_check_proof (const char *proof,
+                          const struct GNUNET_HashCode *key);
+
+
+/**
+ * Iterator callback function.
+ *
+ * @param cls closure.
+ * @param key hash for current state.
+ * @param proof proof for current state.
+ * @param accepting GNUNET_YES if this is an accepting state, GNUNET_NO if not.
+ * @param num_edges number of edges leaving current state.
+ * @param edges edges leaving current state.
+ */
+typedef void (*REGEX_ITERNAL_KeyIterator)(void *cls,
+                                         const struct GNUNET_HashCode *key,
+                                         const char *proof,
+                                         int accepting,
+                                         unsigned int num_edges,
+                                         const struct REGEX_ITERNAL_Edge *edges);
+
+
+/**
+ * Iterate over all edges starting from start state of automaton 'a'. Calling
+ * iterator for each edge.
+ *
+ * @param a automaton.
+ * @param iterator iterator called for each edge.
+ * @param iterator_cls closure.
+ */
+void
+REGEX_ITERNAL_iterate_all_edges (struct REGEX_ITERNAL_Automaton *a,
+                                REGEX_ITERNAL_KeyIterator iterator,
+                                void *iterator_cls);
+
+
+
+/**
+ * Handle to store cached data about a regex announce.
+ */
+struct REGEX_ITERNAL_Announcement;
+
+/**
+ * Handle to store data about a regex search.
+ */
+struct REGEX_ITERNAL_Search;
+
+/**
+ * Announce a regular expression: put all states of the automaton in the DHT.
+ * Does not free resources, must call REGEX_ITERNAL_announce_cancel for that.
+ * 
+ * @param dht An existing and valid DHT service handle. CANNOT be NULL.
+ * @param id ID to announce as provider of regex. Own ID in most cases.
+ * @param regex Regular expression to announce.
+ * @param compression How many characters per edge can we squeeze?
+ * @param stats Optional statistics handle to report usage. Can be NULL.
+ * 
+ * @return Handle to reuse o free cached resources.
+ *         Must be freed by calling REGEX_ITERNAL_announce_cancel.
+ */
+struct REGEX_ITERNAL_Announcement *
+REGEX_ITERNAL_announce (struct GNUNET_DHT_Handle *dht,
+                       const struct GNUNET_PeerIdentity *id,
+                       const char *regex,
+                       uint16_t compression,
+                       struct GNUNET_STATISTICS_Handle *stats);
+
+/**
+ * Announce again a regular expression previously announced.
+ * Does use caching to speed up process.
+ * 
+ * @param h Handle returned by a previous REGEX_ITERNAL_announce call.
+ */
+void
+REGEX_ITERNAL_reannounce (struct REGEX_ITERNAL_Announcement *h);
+
+
+/**
+ * Clear all cached data used by a regex announce.
+ * Does not close DHT connection.
+ * 
+ * @param h Handle returned by a previous REGEX_ITERNAL_announce call.
+ */
+void
+REGEX_ITERNAL_announce_cancel (struct REGEX_ITERNAL_Announcement *h);
+
+
+/**
+ * Search callback function.
+ *
+ * @param cls Closure provided in REGEX_ITERNAL_search.
+ * @param id Peer providing a regex that matches the string.
+ * @param get_path Path of the get request.
+ * @param get_path_length Lenght of get_path.
+ * @param put_path Path of the put request.
+ * @param put_path_length Length of the put_path.
+ */
+typedef void (*REGEX_ITERNAL_Found)(void *cls,
+                                   const struct GNUNET_PeerIdentity *id,
+                                   const struct GNUNET_PeerIdentity *get_path,
+                                   unsigned int get_path_length,
+                                   const struct GNUNET_PeerIdentity *put_path,
+                                   unsigned int put_path_length);
+
+
+/**
+ * Search for a peer offering a regex matching certain string in the DHT.
+ * The search runs until REGEX_ITERNAL_search_cancel is called, even if results
+ * are returned.
+ *
+ * @param dht An existing and valid DHT service handle.
+ * @param string String to match against the regexes in the DHT.
+ * @param callback Callback for found peers.
+ * @param callback_cls Closure for @c callback.
+ * @param stats Optional statistics handle to report usage. Can be NULL.
+ * 
+ * @return Handle to stop search and free resources.
+ *         Must be freed by calling REGEX_ITERNAL_search_cancel.
+ */
+struct REGEX_ITERNAL_Search *
+REGEX_ITERNAL_search (struct GNUNET_DHT_Handle *dht,
+                     const char *string,
+                     REGEX_ITERNAL_Found callback,
+                     void *callback_cls,
+                     struct GNUNET_STATISTICS_Handle *stats);
+
+/**
+ * Stop search and free all data used by a REGEX_ITERNAL_search call.
+ * Does not close DHT connection.
+ * 
+ * @param h Handle returned by a previous REGEX_ITERNAL_search call.
+ */
+void
+REGEX_ITERNAL_search_cancel (struct REGEX_ITERNAL_Search *h);
+
+
+#if 0                           /* keep Emacsens' auto-indent happy */
+{
+#endif
+#ifdef __cplusplus
+}
+#endif
+
+/* end of regex_internal_lib.h */
+#endif