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/*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 2001 Gerald Combs
*
* This program 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 2
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/* Perl-Compatible Regular Expression (PCRE) internal field type.
* Used with the "matches" dfilter operator, allowing efficient
* compilation and studying of a PCRE pattern in dfilters.
*/
#include "config.h"
#include <ftypes-int.h>
#include <glib.h>
#include <string.h>
static void
gregex_fvalue_new(fvalue_t *fv)
{
fv->value.re = NULL;
}
static void
gregex_fvalue_free(fvalue_t *fv)
{
if (fv->value.re) {
g_regex_unref(fv->value.re);
fv->value.re = NULL;
}
}
/* Determines whether pattern needs to match raw byte sequences */
static gboolean
raw_flag_needed(const gchar *pattern)
{
gboolean found = FALSE;
const gchar *s = pattern;
size_t i, len;
/* find any character whose hex value is two letters */
len = strlen(s);
for (i = 0; i < len; i++) {
/* Upper and lower-nibble must be >= 0xA */
if ((guchar)(s[i] & 0xF0) >= 0xA0 &&
(guchar)(s[i] & 0x0F) >= 0x0A)
{
found = TRUE;
break;
}
}
return found;
}
/* Generate a FT_PCRE from a parsed string pattern.
* On failure, if err_msg is non-null, set *err_msg to point to a
* g_malloc()ed error message. */
static gboolean
val_from_string(fvalue_t *fv, const char *pattern, gchar **err_msg)
{
GError *regex_error = NULL;
GRegexCompileFlags cflags = (GRegexCompileFlags)(G_REGEX_CASELESS | G_REGEX_OPTIMIZE);
/* Set RAW flag only if pattern requires matching raw byte
sequences. Otherwise, omit it so that GRegex treats its
input as UTF8-encoded string. */
if (raw_flag_needed(pattern)) {
cflags = (GRegexCompileFlags)(cflags | G_REGEX_RAW);
}
/* Free up the old value, if we have one */
gregex_fvalue_free(fv);
fv->value.re = g_regex_new(
pattern, /* pattern */
cflags, /* Compile options */
(GRegexMatchFlags)0, /* Match options */
®ex_error /* Compile / study errors */
);
if (regex_error) {
if (err_msg) {
*err_msg = g_strdup(regex_error->message);
}
g_error_free(regex_error);
if (fv->value.re) {
g_regex_unref(fv->value.re);
}
return FALSE;
}
return TRUE;
}
/* Generate a FT_PCRE from an unparsed string pattern.
* On failure, if err_msg is non-null, set *err_msg to point to a
* g_malloc()ed error message. */
static gboolean
val_from_unparsed(fvalue_t *fv, const char *pattern, gboolean allow_partial_value, gchar **err_msg)
{
g_assert(! allow_partial_value);
return val_from_string(fv, pattern, err_msg);
}
static int
gregex_repr_len(fvalue_t *fv, ftrepr_t rtype, int field_display _U_)
{
g_assert(rtype == FTREPR_DFILTER);
return (int)strlen(g_regex_get_pattern(fv->value.re));
}
static void
gregex_to_repr(fvalue_t *fv, ftrepr_t rtype, int field_display _U_, char *buf, unsigned int size)
{
g_assert(rtype == FTREPR_DFILTER);
g_strlcpy(buf, g_regex_get_pattern(fv->value.re), size);
}
/* BEHOLD - value contains the string representation of the regular expression,
* and we want to store the compiled PCRE RE object into the value. */
static void
gregex_fvalue_set(fvalue_t *fv, const char *value)
{
g_assert(value != NULL);
/* Free up the old value, if we have one */
gregex_fvalue_free(fv);
val_from_unparsed(fv, value, FALSE, NULL);
}
static gpointer
gregex_fvalue_get(fvalue_t *fv)
{
return fv->value.re;
}
void
ftype_register_pcre(void)
{
static ftype_t pcre_type = {
FT_PCRE, /* ftype */
"FT_PCRE", /* name */
"Compiled Perl-Compatible Regular Expression (GRegex) object", /* pretty_name */
0, /* wire_size */
gregex_fvalue_new, /* new_value */
gregex_fvalue_free, /* free_value */
val_from_unparsed, /* val_from_unparsed */
val_from_string, /* val_from_string */
gregex_to_repr, /* val_to_string_repr */
gregex_repr_len, /* len_string_repr */
{ .set_value_string = gregex_fvalue_set }, /* union set_value */
{ .get_value_ptr = gregex_fvalue_get }, /* union get_value */
NULL, /* cmp_eq */
NULL, /* cmp_ne */
NULL, /* cmp_gt */
NULL, /* cmp_ge */
NULL, /* cmp_lt */
NULL, /* cmp_le */
NULL, /* cmp_bitwise_and */
NULL, /* cmp_contains */
NULL, /* cmp_matches */
NULL, /* len */
NULL, /* slice */
};
ftype_register(FT_PCRE, &pcre_type);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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