diff options
Diffstat (limited to 'server/util_regex.c')
| -rw-r--r-- | server/util_regex.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/server/util_regex.c b/server/util_regex.c new file mode 100644 index 0000000..5405f8d --- /dev/null +++ b/server/util_regex.c @@ -0,0 +1,211 @@ +/* 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_pstrmemdup(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_pstrmemdup(pool, str, endp-str); + } + + /* anything after the current delimiter is flags */ + ret->flags = ap_regcomp_get_default_cflags() & AP_REG_DOLLAR_ENDONLY; + 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, AP_REG_NO_DEFAULT | 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); +} |