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);
+}