MaxScale/server/core/maxscale_pcre2.c

136 lines
4.3 KiB
C

/*
* Copyright (c) 2016 MariaDB Corporation Ab
*
* Use of this software is governed by the Business Source License included
* in the LICENSE.TXT file and at www.mariadb.com/bsl.
*
* Change Date: 2019-07-01
*
* On the date above, in accordance with the Business Source License, use
* of this software will be governed by version 2 or later of the General
* Public License.
*
*/
/**
* @file maxscale_pcre2.c - Utility functions for regular expression matching
* with the bundled PCRE2 library.
*
* @verbatim
* Revision History
*
* Date Who Description
* 30-10-2015 Markus Makela Initial implementation
* @endverbatim
*/
#include <maxscale/pcre2.h>
#include <maxscale/alloc.h>
/**
* Utility wrapper for PCRE2 library function call pcre2_substitute.
*
* This function replaces all occurences of a pattern with the provided replacement
* and places the end result into @c dest. This buffer must be allocated by the caller.
* If the size of @c dest is not large enough it will be reallocated to a larger size.
* The size of @c dest is stored in @c size if any reallocation takes place.
*
* @param re Compiled pattern to use
* @param subject Subject string
* @param replace Replacement string
* @param dest Destination buffer
* @param size Size of the desination buffer
* @return MXS_PCRE2_MATCH if replacements were made, MXS_PCRE2_NOMATCH if nothing
* was replaced or MXS_PCRE2_ERROR if memory reallocation failed
*/
mxs_pcre2_result_t mxs_pcre2_substitute(pcre2_code *re, const char *subject, const char *replace,
char** dest, size_t* size)
{
int rc;
mxs_pcre2_result_t rval = MXS_PCRE2_ERROR;
pcre2_match_data *mdata = pcre2_match_data_create_from_pattern(re, NULL);
if (mdata)
{
while ((rc = pcre2_substitute(re, (PCRE2_SPTR) subject, PCRE2_ZERO_TERMINATED, 0,
PCRE2_SUBSTITUTE_GLOBAL, mdata, NULL,
(PCRE2_SPTR) replace, PCRE2_ZERO_TERMINATED,
(PCRE2_UCHAR*) *dest, size)) == PCRE2_ERROR_NOMEMORY)
{
char *tmp = MXS_REALLOC(*dest, *size * 2);
if (tmp == NULL)
{
break;
}
*dest = tmp;
*size *= 2;
}
if (rc > 0)
{
rval = MXS_PCRE2_MATCH;
}
else if (rc == 0)
{
rval = MXS_PCRE2_NOMATCH;
}
pcre2_match_data_free(mdata);
}
return rval;
}
/**
* Do a simple matching of a pattern to a string.
*
* This function compiles the given pattern and checks if the subject string matches
* it.
* @param pattern Pattern used for matching
* @param subject Subject string to match
* @param options PCRE2 compilation options
* @param error The PCRE2 error code is stored here if one is available
* @return MXS_PCRE2_MATCH if @c subject matches @c pattern, MXS_PCRE2_NOMATCH if
* they do not match and MXS_PCRE2_ERROR if an error occurred. If an error occurred
* within the PCRE2 library, @c error will contain the error code. Otherwise it is
* set to 0.
*/
mxs_pcre2_result_t mxs_pcre2_simple_match(const char* pattern, const char* subject,
int options, int *error)
{
int err;
size_t erroff;
mxs_pcre2_result_t rval = MXS_PCRE2_ERROR;
pcre2_code *re = pcre2_compile((PCRE2_SPTR) pattern, PCRE2_ZERO_TERMINATED,
options, &err, &erroff, NULL);
if (re)
{
pcre2_match_data *mdata = pcre2_match_data_create_from_pattern(re, NULL);
if (mdata)
{
int rc = pcre2_match(re, (PCRE2_SPTR) subject, PCRE2_ZERO_TERMINATED,
0, 0, mdata, NULL);
if (rc == PCRE2_ERROR_NOMATCH)
{
rval = MXS_PCRE2_NOMATCH;
}
else if (rc > 0)
{
/** Since we used the pattern to create the matching data,
* pcre2_match will never return 0 */
rval = MXS_PCRE2_MATCH;
}
pcre2_match_data_free(mdata);
}
else
{
*error = 0;
}
pcre2_code_free(re);
}
else
{
*error = err;
}
return rval;
}