/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "apr.h"
#include "apr_lib.h"
#include "apr_pools.h"
#include "apr_strings.h"
#include "ap_config.h"
#include "ap_regex.h"
#include "httpd.h"
static apr_status_t rxplus_cleanup(void *preg)
{
ap_regfree((ap_regex_t *) preg);
return APR_SUCCESS;
}
AP_DECLARE(ap_rxplus_t*) ap_rxplus_compile(apr_pool_t *pool,
const char *pattern)
{
/* perl style patterns
* add support for more as and when wanted
* substitute: s/rx/subs/
* match: m/rx/ or just /rx/
*/
/* allow any nonalnum delimiter as first or second char.
* If we ever use this with non-string pattern we'll need an extra check
*/
const char *endp = 0;
const char *str = pattern;
const char *rxstr;
ap_rxplus_t *ret = apr_pcalloc(pool, sizeof(ap_rxplus_t));
char delim = 0;
enum { SUBSTITUTE = 's', MATCH = 'm'} action = MATCH;
if (!apr_isalnum(pattern[0])) {
delim = *str++;
}
else if (pattern[0] == 's' && !apr_isalnum(pattern[1])) {
action = SUBSTITUTE;
delim = pattern[1];
str += 2;
}
else if (pattern[0] == 'm' && !apr_isalnum(pattern[1])) {
delim = pattern[1];
str += 2;
}
/* TODO: support perl's after/before */
/* FIXME: fix these simplminded delims */
/* we think there's a delimiter. Allow for it not to be if unmatched */
if (delim) {
endp = ap_strchr_c(str, delim);
}
if (!endp) { /* there's no delim or flags */
if (ap_regcomp(&ret->rx, pattern, 0) == 0) {
apr_pool_cleanup_register(pool, &ret->rx, rxplus_cleanup,
apr_pool_cleanup_null);
return ret;
}
else {
return NULL;
}
}
/* We have a delimiter. Use it to extract the regexp */
rxstr = apr_pstrndup(pool, str, endp-str);
/* If it's a substitution, we need the replacement string
* TODO: possible future enhancement - support other parsing
* in the replacement string.
*/
if (action == SUBSTITUTE) {
str = endp+1;
if (!*str || (endp = ap_strchr_c(str, delim), !endp)) {
/* missing replacement string is an error */
return NULL;
}
ret->subs = apr_pstrndup(pool, str, (endp-str));
}
/* anything after the current delimiter is flags */
while (*++endp) {
switch (*endp) {
case 'i': ret->flags |= AP_REG_ICASE; break;
case 'm': ret->flags |= AP_REG_NEWLINE; break;
case 'n': ret->flags |= AP_REG_NOMEM; break;
case 'g': ret->flags |= AP_REG_MULTI; break;
case 's': ret->flags |= AP_REG_DOTALL; break;
case '^': ret->flags |= AP_REG_NOTBOL; break;
case '$': ret->flags |= AP_REG_NOTEOL; break;
default: break; /* we should probably be stricter here */
}
}
if (ap_regcomp(&ret->rx, rxstr, ret->flags) == 0) {
apr_pool_cleanup_register(pool, &ret->rx, rxplus_cleanup,
apr_pool_cleanup_null);
}
else {
return NULL;
}
if (!(ret->flags & AP_REG_NOMEM)) {
/* count size of memory required, starting at 1 for the whole-match
* Simpleminded should be fine 'cos regcomp already checked syntax
*/
ret->nmatch = 1;
while (*rxstr) {
switch (*rxstr++) {
case '\\': /* next char is escaped - skip it */
if (*rxstr != 0) {
++rxstr;
}
break;
case '(': /* unescaped bracket implies memory */
++ret->nmatch;
break;
default:
break;
}
}
ret->pmatch = apr_palloc(pool, ret->nmatch*sizeof(ap_regmatch_t));
}
return ret;
}
AP_DECLARE(int) ap_rxplus_exec(apr_pool_t *pool, ap_rxplus_t *rx,
const char *pattern, char **newpattern)
{
int ret = 1;
int startl, oldl, newl, diffsz;
const char *remainder;
char *subs;
/* snrf process_regexp from mod_headers */
if (ap_regexec(&rx->rx, pattern, rx->nmatch, rx->pmatch, rx->flags) != 0) {
rx->match = NULL;
return 0; /* no match, nothing to do */
}
rx->match = pattern;
if (rx->subs) {
*newpattern = ap_pregsub(pool, rx->subs, pattern,
rx->nmatch, rx->pmatch);
if (!*newpattern) {
return 0; /* FIXME - should we do more to handle error? */
}
startl = rx->pmatch[0].rm_so;
oldl = rx->pmatch[0].rm_eo - startl;
newl = strlen(*newpattern);
diffsz = newl - oldl;
remainder = pattern + startl + oldl;
if (rx->flags & AP_REG_MULTI) {
/* recurse to do any further matches */
ret += ap_rxplus_exec(pool, rx, remainder, &subs);
if (ret > 1) {
/* a further substitution happened */
diffsz += strlen(subs) - strlen(remainder);
remainder = subs;
}
}
subs = apr_palloc(pool, strlen(pattern) + 1 + diffsz);
memcpy(subs, pattern, startl);
memcpy(subs+startl, *newpattern, newl);
strcpy(subs+startl+newl, remainder);
*newpattern = subs;
}
return ret;
}
#ifdef DOXYGEN
AP_DECLARE(int) ap_rxplus_nmatch(ap_rxplus_t *rx)
{
return (rx->match != NULL) ? rx->nmatch : 0;
}
#endif
/* If this blows up on you, see the notes in the header/apidoc
* rx->match is a pointer and it's your responsibility to ensure
* it hasn't gone out-of-scope since the last ap_rxplus_exec
*/
AP_DECLARE(void) ap_rxplus_match(ap_rxplus_t *rx, int n, int *len,
const char **match)
{
if (n >= 0 && n < ap_rxplus_nmatch(rx)) {
*match = rx->match + rx->pmatch[n].rm_so;
*len = rx->pmatch[n].rm_eo - rx->pmatch[n].rm_so;
}
else {
*len = -1;
*match = NULL;
}
}
AP_DECLARE(char*) ap_rxplus_pmatch(apr_pool_t *pool, ap_rxplus_t *rx, int n)
{
int len;
const char *match;
ap_rxplus_match(rx, n, &len, &match);
return apr_pstrndup(pool, match, len);
}