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+/* 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.
+ */
+
+/*
+ * mod_cern_meta.c
+ * version 0.1.0
+ * status beta
+ *
+ * Andrew Wilson <Andrew.Wilson@cm.cf.ac.uk> 25.Jan.96
+ *
+ * *** IMPORTANT ***
+ * This version of mod_cern_meta.c controls Meta File behaviour on a
+ * per-directory basis. Previous versions of the module defined behaviour
+ * on a per-server basis. The upshot is that you'll need to revisit your
+ * configuration files in order to make use of the new module.
+ * ***
+ *
+ * Emulate the CERN HTTPD Meta file semantics. Meta files are HTTP
+ * headers that can be output in addition to the normal range of
+ * headers for each file accessed. They appear rather like the Apache
+ * .asis files, and are able to provide a crude way of influencing
+ * the Expires: header, as well as providing other curiosities.
+ * There are many ways to manage meta information, this one was
+ * chosen because there is already a large number of CERN users
+ * who can exploit this module. It should be noted that there are probably
+ * more sensitive ways of managing the Expires: header specifically.
+ *
+ * The module obeys the following directives, which can appear
+ * in the server's .conf files and in .htaccess files.
+ *
+ * MetaFiles <on|off>
+ *
+ * turns on|off meta file processing for any directory.
+ * Default value is off
+ *
+ * # turn on MetaFiles in this directory
+ * MetaFiles on
+ *
+ * MetaDir <directory name>
+ *
+ * specifies the name of the directory in which Apache can find
+ * meta information files. The directory is usually a 'hidden'
+ * subdirectory of the directory that contains the file being
+ * accessed. eg:
+ *
+ * # .meta files are in the *same* directory as the
+ * # file being accessed
+ * MetaDir .
+ *
+ * the default is to look in a '.web' subdirectory. This is the
+ * same as for CERN 3.+ webservers and behaviour is the same as
+ * for the directive:
+ *
+ * MetaDir .web
+ *
+ * MetaSuffix <meta file suffix>
+ *
+ * specifies the file name suffix for the file containing the
+ * meta information. eg:
+ *
+ * # our meta files are suffixed with '.cern_meta'
+ * MetaSuffix .cern_meta
+ *
+ * the default is to look for files with the suffix '.meta'. This
+ * behaviour is the same as for the directive:
+ *
+ * MetaSuffix .meta
+ *
+ * When accessing the file
+ *
+ * DOCUMENT_ROOT/somedir/index.html
+ *
+ * this module will look for the file
+ *
+ * DOCUMENT_ROOT/somedir/.web/index.html.meta
+ *
+ * and will use its contents to generate additional MIME header
+ * information.
+ *
+ * For more information on the CERN Meta file semantics see:
+ *
+ * http://www.w3.org/hypertext/WWW/Daemon/User/Config/General.html#MetaDir
+ *
+ * Change-log:
+ * 29.Jan.96 pfopen/pfclose instead of fopen/fclose
+ * DECLINE when real file not found, we may be checking each
+ * of the index.html/index.shtml/index.htm variants and don't
+ * need to report missing ones as spurious errors.
+ * 31.Jan.96 log_error reports about a malformed .meta file, rather
+ * than a script error.
+ * 20.Jun.96 MetaFiles <on|off> default off, added, so that module
+ * can be configured per-directory. Prior to this the module
+ * was running for each request anywhere on the server, naughty..
+ * 29.Jun.96 All directives made per-directory.
+ */
+
+#include "apr.h"
+#include "apr_strings.h"
+
+#define APR_WANT_STRFUNC
+#include "apr_want.h"
+
+#if APR_HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#include "ap_config.h"
+#include "httpd.h"
+#include "http_config.h"
+#include "util_script.h"
+#include "http_log.h"
+#include "http_request.h"
+#include "http_protocol.h"
+#include "apr_lib.h"
+
+#define DIR_CMD_PERMS OR_INDEXES
+
+#define DEFAULT_METADIR ".web"
+#define DEFAULT_METASUFFIX ".meta"
+#define DEFAULT_METAFILES 0
+
+module AP_MODULE_DECLARE_DATA cern_meta_module;
+
+typedef struct {
+ const char *metadir;
+ const char *metasuffix;
+ int metafiles;
+} cern_meta_dir_config;
+
+static void *create_cern_meta_dir_config(apr_pool_t *p, char *dummy)
+{
+ cern_meta_dir_config *new =
+ (cern_meta_dir_config *) apr_palloc(p, sizeof(cern_meta_dir_config));
+
+ new->metadir = NULL;
+ new->metasuffix = NULL;
+ new->metafiles = DEFAULT_METAFILES;
+
+ return new;
+}
+
+static void *merge_cern_meta_dir_configs(apr_pool_t *p, void *basev, void *addv)
+{
+ cern_meta_dir_config *base = (cern_meta_dir_config *) basev;
+ cern_meta_dir_config *add = (cern_meta_dir_config *) addv;
+ cern_meta_dir_config *new =
+ (cern_meta_dir_config *) apr_palloc(p, sizeof(cern_meta_dir_config));
+
+ new->metadir = add->metadir ? add->metadir : base->metadir;
+ new->metasuffix = add->metasuffix ? add->metasuffix : base->metasuffix;
+ new->metafiles = add->metafiles;
+
+ return new;
+}
+
+static const char *set_metadir(cmd_parms *parms, void *in_dconf, const char *arg)
+{
+ cern_meta_dir_config *dconf = in_dconf;
+
+ dconf->metadir = arg;
+ return NULL;
+}
+
+static const char *set_metasuffix(cmd_parms *parms, void *in_dconf, const char *arg)
+{
+ cern_meta_dir_config *dconf = in_dconf;
+
+ dconf->metasuffix = arg;
+ return NULL;
+}
+
+static const char *set_metafiles(cmd_parms *parms, void *in_dconf, int arg)
+{
+ cern_meta_dir_config *dconf = in_dconf;
+
+ dconf->metafiles = arg;
+ return NULL;
+}
+
+
+static const command_rec cern_meta_cmds[] =
+{
+ AP_INIT_FLAG("MetaFiles", set_metafiles, NULL, DIR_CMD_PERMS,
+ "Limited to 'on' or 'off'"),
+ AP_INIT_TAKE1("MetaDir", set_metadir, NULL, DIR_CMD_PERMS,
+ "the name of the directory containing meta files"),
+ AP_INIT_TAKE1("MetaSuffix", set_metasuffix, NULL, DIR_CMD_PERMS,
+ "the filename suffix for meta files"),
+ {NULL}
+};
+
+/* XXX: this is very similar to ap_scan_script_header_err_core...
+ * are the differences deliberate, or just a result of bit rot?
+ */
+static int scan_meta_file(request_rec *r, apr_file_t *f)
+{
+ char w[MAX_STRING_LEN];
+ char *l;
+ int p;
+ apr_table_t *tmp_headers;
+
+ tmp_headers = apr_table_make(r->pool, 5);
+ while (apr_file_gets(w, MAX_STRING_LEN - 1, f) == APR_SUCCESS) {
+
+ /* Delete terminal (CR?)LF */
+ p = strlen(w);
+ if (p > 0 && w[p - 1] == '\n') {
+ if (p > 1 && w[p - 2] == '\015')
+ w[p - 2] = '\0';
+ else
+ w[p - 1] = '\0';
+ }
+
+ if (w[0] == '\0') {
+ return OK;
+ }
+
+ /* if we see a bogus header don't ignore it. Shout and scream */
+
+ if (!(l = strchr(w, ':'))) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01560)
+ "malformed header in meta file: %s", r->filename);
+ return HTTP_INTERNAL_SERVER_ERROR;
+ }
+
+ *l++ = '\0';
+ while (apr_isspace(*l))
+ ++l;
+
+ if (!strcasecmp(w, "Content-type")) {
+ char *tmp;
+ /* Nuke trailing whitespace */
+
+ char *endp = l + strlen(l) - 1;
+ while (endp > l && apr_isspace(*endp))
+ *endp-- = '\0';
+
+ tmp = apr_pstrdup(r->pool, l);
+ ap_content_type_tolower(tmp);
+ ap_set_content_type(r, tmp);
+ }
+ else if (!strcasecmp(w, "Status")) {
+ sscanf(l, "%d", &r->status);
+ r->status_line = apr_pstrdup(r->pool, l);
+ }
+ else {
+ apr_table_set(tmp_headers, w, l);
+ }
+ }
+ apr_table_overlap(r->headers_out, tmp_headers, APR_OVERLAP_TABLES_SET);
+ return OK;
+}
+
+static int add_cern_meta_data(request_rec *r)
+{
+ char *metafilename;
+ char *leading_slash;
+ char *last_slash;
+ char *real_file;
+ char *scrap_book;
+ apr_file_t *f = NULL;
+ apr_status_t retcode;
+ cern_meta_dir_config *dconf;
+ int rv;
+ request_rec *rr;
+
+ dconf = ap_get_module_config(r->per_dir_config, &cern_meta_module);
+
+ if (!dconf->metafiles) {
+ return DECLINED;
+ }
+
+ /* if ./.web/$1.meta exists then output 'asis' */
+
+ if (r->finfo.filetype == APR_NOFILE) {
+ return DECLINED;
+ }
+
+ /* is this a directory? */
+ if (r->finfo.filetype == APR_DIR || r->uri[strlen(r->uri) - 1] == '/') {
+ return DECLINED;
+ }
+
+ /* what directory is this file in? */
+ scrap_book = apr_pstrdup(r->pool, r->filename);
+
+ leading_slash = strchr(scrap_book, '/');
+ last_slash = strrchr(scrap_book, '/');
+ if ((last_slash != NULL) && (last_slash != leading_slash)) {
+ /* skip over last slash */
+ real_file = last_slash;
+ real_file++;
+ *last_slash = '\0';
+ }
+ else {
+ /* no last slash, buh?! */
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01561)
+ "internal error in mod_cern_meta: %s", r->filename);
+ /* should really barf, but hey, let's be friends... */
+ return DECLINED;
+ }
+
+ metafilename = apr_pstrcat(r->pool, scrap_book, "/",
+ dconf->metadir ? dconf->metadir : DEFAULT_METADIR,
+ "/", real_file,
+ dconf->metasuffix ? dconf->metasuffix : DEFAULT_METASUFFIX,
+ NULL);
+
+ /* It sucks to require this subrequest to complete, because this
+ * means people must leave their meta files accessible to the world.
+ * A better solution might be a "safe open" feature of pfopen to avoid
+ * pipes, symlinks, and crap like that.
+ *
+ * In fact, this doesn't suck. Because <Location > blocks are never run
+ * against sub_req_lookup_file, the meta can be somewhat protected by
+ * either masking it with a <Location > directive or alias, or stowing
+ * the file outside of the web document tree, while providing the
+ * appropriate directory blocks to allow access to it as a file.
+ */
+ rr = ap_sub_req_lookup_file(metafilename, r, NULL);
+ if (rr->status != HTTP_OK) {
+ ap_destroy_sub_req(rr);
+ return DECLINED;
+ }
+ ap_destroy_sub_req(rr);
+
+ retcode = apr_file_open(&f, metafilename, APR_READ, APR_OS_DEFAULT, r->pool);
+ if (retcode != APR_SUCCESS) {
+ if (APR_STATUS_IS_ENOENT(retcode)) {
+ return DECLINED;
+ }
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01562)
+ "meta file permissions deny server access: %s", metafilename);
+ return HTTP_FORBIDDEN;
+ }
+
+ /* read the headers in */
+ rv = scan_meta_file(r, f);
+ apr_file_close(f);
+
+ return rv;
+}
+
+static void register_hooks(apr_pool_t *p)
+{
+ ap_hook_fixups(add_cern_meta_data,NULL,NULL,APR_HOOK_MIDDLE);
+}
+
+AP_DECLARE_MODULE(cern_meta) =
+{
+ STANDARD20_MODULE_STUFF,
+ create_cern_meta_dir_config, /* dir config creater */
+ merge_cern_meta_dir_configs, /* dir merger --- default is to override */
+ NULL, /* server config */
+ NULL, /* merge server configs */
+ cern_meta_cmds, /* command apr_table_t */
+ register_hooks /* register hooks */
+};
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