1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements. See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License. You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
22 * Andrew Wilson <Andrew.Wilson@cm.cf.ac.uk> 26.Jan.96
24 * This module allows you to control the form of the Expires: header
25 * that Apache issues for each access. Directives can appear in
26 * configuration files or in .htaccess files so expiry semantics can
27 * be defined on a per-directory basis.
31 * Valid directives are:
33 * ExpiresActive on | off
34 * ExpiresDefault <code><seconds>
35 * ExpiresByType type/encoding <code><seconds>
37 * Valid values for <code> are:
39 * 'M' expires header shows file modification date + <seconds>
40 * 'A' expires header shows access time + <seconds>
42 * [I'm not sure which of these is best under different
43 * circumstances, I guess it's for other people to explore.
44 * The effects may be indistinguishable for a number of cases]
46 * <seconds> should be an integer value [acceptable to atoi()]
48 * There is NO space between the <code> and <seconds>.
50 * For example, a directory which contains information which changes
51 * frequently might contain:
53 * # reports generated by cron every hour. don't let caches
54 * # hold onto stale information
55 * ExpiresDefault M3600
57 * Another example, our html pages can change all the time, the gifs
58 * tend not to change often:
60 * # pages are hot (1 week), images are cold (1 month)
61 * ExpiresByType text/html A604800
62 * ExpiresByType image/gif A2592000
64 * Expires can be turned on for all URLs on the server by placing the
65 * following directive in a conf file:
69 * ExpiresActive can also appear in .htaccess files, enabling the
70 * behaviour to be turned on or off for each chosen directory.
72 * # turn off Expires behaviour in this directory
73 * # and subdirectories
76 * Directives defined for a directory are valid in subdirectories
77 * unless explicitly overridden by new directives in the subdirectory
80 * ALTERNATIVE DIRECTIVE SYNTAX
82 * Directives can also be defined in a more readable syntax of the form:
84 * ExpiresDefault "<base> [plus] {<num> <type>}*"
85 * ExpiresByType type/encoding "<base> [plus] {<num> <type>}*"
87 * where <base> is one of:
89 * now equivalent to 'access'
92 * where the 'plus' keyword is optional
94 * where <num> should be an integer value [acceptable to atoi()]
96 * where <type> is one of:
105 * For example, any of the following directives can be used to make
106 * documents expire 1 month after being accessed, by default:
108 * ExpiresDefault "access plus 1 month"
109 * ExpiresDefault "access plus 4 weeks"
110 * ExpiresDefault "access plus 30 days"
112 * The expiry time can be fine-tuned by adding several '<num> <type>'
115 * ExpiresByType text/html "access plus 1 month 15 days 2 hours"
116 * ExpiresByType image/gif "modification plus 5 hours 3 minutes"
121 * 29.Jan.96 Hardened the add_* functions. Server will now bail out
122 * if bad directives are given in the conf files.
123 * 02.Feb.96 Returns DECLINED if not 'ExpiresActive on', giving other
124 * expires-aware modules a chance to play with the same
125 * directives. [Michael Rutman]
126 * 03.Feb.96 Call tzset() before localtime(). Trying to get the module
127 * to work properly in non GMT timezones.
128 * 12.Feb.96 Modified directive syntax to allow more readable commands:
129 * ExpiresDefault "now plus 10 days 20 seconds"
130 * ExpiresDefault "access plus 30 days"
131 * ExpiresDefault "modification plus 1 year 10 months 30 days"
132 * 13.Feb.96 Fix call to table_get() with NULL 2nd parameter [Rob Hartill]
133 * 19.Feb.96 Call gm_timestr_822() to get time formatted correctly, can't
134 * rely on presence of HTTP_TIME_FORMAT in Apache 1.1+.
135 * 21.Feb.96 This version (0.0.9) reverses assumptions made in 0.0.8
136 * about star/star handlers. Reverting to 0.0.7 behaviour.
137 * 08.Jun.96 allows ExpiresDefault to be used with responses that use
138 * the DefaultType by not DECLINING, but instead skipping
139 * the table_get check and then looking for an ExpiresDefault.
141 * 04.Nov.96 'const' definitions added.
144 * add support for Cache-Control: max-age=20 from the HTTP/1.1
145 * proposal (in this case, a ttl of 20 seconds) [ask roy]
146 * add per-file expiry and explicit expiry times - duplicates some
147 * of the mod_cern_meta.c functionality. eg:
148 * ExpiresExplicit index.html "modification plus 30 days"
151 * Hi, welcome to the internet.
155 #include "apr_strings.h"
158 #define APR_WANT_STRFUNC
159 #include "apr_want.h"
161 #include "ap_config.h"
163 #include "http_config.h"
164 #include "http_log.h"
165 #include "http_request.h"
166 #include "http_protocol.h"
171 char *expiresdefault;
172 apr_table_t *expiresbytype;
173 } expires_dir_config;
175 /* from mod_dir, why is this alias used?
177 #define DIR_CMD_PERMS OR_INDEXES
181 #define ACTIVE_DONTCARE 2
183 module AP_MODULE_DECLARE_DATA expires_module;
185 static void *create_dir_expires_config(apr_pool_t *p, char *dummy)
187 expires_dir_config *new =
188 (expires_dir_config *) apr_pcalloc(p, sizeof(expires_dir_config));
189 new->active = ACTIVE_DONTCARE;
191 new->expiresdefault = NULL;
192 new->expiresbytype = apr_table_make(p, 4);
196 static const char *set_expiresactive(cmd_parms *cmd, void *in_dir_config, int arg)
198 expires_dir_config *dir_config = in_dir_config;
200 /* if we're here at all it's because someone explicitly
201 * set the active flag
203 dir_config->active = ACTIVE_ON;
205 dir_config->active = ACTIVE_OFF;
210 /* check_code() parse 'code' and return NULL or an error response
211 * string. If we return NULL then real_code contains code converted
212 * to the cnnnn format.
214 static char *check_code(apr_pool_t *p, const char *code, char **real_code)
222 /* 0.0.4 compatibility?
224 if ((code[0] == 'A') || (code[0] == 'M')) {
225 *real_code = (char *)code;
229 /* <base> [plus] {<num> <type>}*
234 word = ap_getword_conf(p, &code);
235 if (!strncasecmp(word, "now", 1) ||
236 !strncasecmp(word, "access", 1)) {
239 else if (!strncasecmp(word, "modification", 1)) {
243 return apr_pstrcat(p, "bad expires code, unrecognised <base> '",
249 word = ap_getword_conf(p, &code);
250 if (!strncasecmp(word, "plus", 1)) {
251 word = ap_getword_conf(p, &code);
259 if (apr_isdigit(word[0])) {
263 return apr_pstrcat(p, "bad expires code, numeric value expected <num> '",
269 word = ap_getword_conf(p, &code);
274 return apr_pstrcat(p, "bad expires code, missing <type>", NULL);
278 if (!strncasecmp(word, "years", 1)) {
279 factor = 60 * 60 * 24 * 365;
281 else if (!strncasecmp(word, "months", 2)) {
282 factor = 60 * 60 * 24 * 30;
284 else if (!strncasecmp(word, "weeks", 1)) {
285 factor = 60 * 60 * 24 * 7;
287 else if (!strncasecmp(word, "days", 1)) {
288 factor = 60 * 60 * 24;
290 else if (!strncasecmp(word, "hours", 1)) {
293 else if (!strncasecmp(word, "minutes", 2)) {
296 else if (!strncasecmp(word, "seconds", 1)) {
300 return apr_pstrcat(p, "bad expires code, unrecognised <type>",
301 "'", word, "'", NULL);
304 modifier = modifier + factor * num;
308 word = ap_getword_conf(p, &code);
311 *real_code = apr_psprintf(p, "%c%d", base, modifier);
316 static const char *set_expiresbytype(cmd_parms *cmd, void *in_dir_config,
317 const char *mime, const char *code)
319 expires_dir_config *dir_config = in_dir_config;
320 char *response, *real_code;
323 check = ap_strrchr_c(mime, '/');
324 if ((strlen(++check) == 1) && (*check == '*')) {
325 dir_config->wildcards = 1;
328 if ((response = check_code(cmd->pool, code, &real_code)) == NULL) {
329 apr_table_setn(dir_config->expiresbytype, mime, real_code);
332 return apr_pstrcat(cmd->pool,
333 "'ExpiresByType ", mime, " ", code, "': ", response, NULL);
336 static const char *set_expiresdefault(cmd_parms *cmd, void *in_dir_config,
339 expires_dir_config * dir_config = in_dir_config;
340 char *response, *real_code;
342 if ((response = check_code(cmd->pool, code, &real_code)) == NULL) {
343 dir_config->expiresdefault = real_code;
346 return apr_pstrcat(cmd->pool,
347 "'ExpiresDefault ", code, "': ", response, NULL);
350 static const command_rec expires_cmds[] =
352 AP_INIT_FLAG("ExpiresActive", set_expiresactive, NULL, DIR_CMD_PERMS,
353 "Limited to 'on' or 'off'"),
354 AP_INIT_TAKE2("ExpiresByType", set_expiresbytype, NULL, DIR_CMD_PERMS,
355 "a MIME type followed by an expiry date code"),
356 AP_INIT_TAKE1("ExpiresDefault", set_expiresdefault, NULL, DIR_CMD_PERMS,
357 "an expiry date code"),
361 static void *merge_expires_dir_configs(apr_pool_t *p, void *basev, void *addv)
363 expires_dir_config *new = (expires_dir_config *) apr_pcalloc(p, sizeof(expires_dir_config));
364 expires_dir_config *base = (expires_dir_config *) basev;
365 expires_dir_config *add = (expires_dir_config *) addv;
367 if (add->active == ACTIVE_DONTCARE) {
368 new->active = base->active;
371 new->active = add->active;
374 if (add->expiresdefault != NULL) {
375 new->expiresdefault = add->expiresdefault;
378 new->expiresdefault = base->expiresdefault;
380 new->wildcards = add->wildcards;
381 new->expiresbytype = apr_table_overlay(p, add->expiresbytype,
382 base->expiresbytype);
387 * Handle the setting of the expiration response header fields according
391 static int set_expiration_fields(request_rec *r, const char *code,
395 apr_time_t additional;
402 if (r->finfo.filetype == 0) {
403 /* file doesn't exist on disk, so we can't do anything based on
404 * modification time. Note that this does _not_ log an error.
408 base = r->finfo.mtime;
409 additional_sec = atoi(&code[1]);
410 additional = apr_time_from_sec(additional_sec);
413 /* there's been some discussion and it's possible that
414 * 'access time' will be stored in request structure
416 base = r->request_time;
417 additional_sec = atoi(&code[1]);
418 additional = apr_time_from_sec(additional_sec);
421 /* expecting the add_* routines to be case-hardened this
422 * is just a reminder that module is beta
424 ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
425 "internal error: bad expires code: %s", r->filename);
426 return HTTP_INTERNAL_SERVER_ERROR;
429 expires = base + additional;
430 if (expires < r->request_time) {
431 expires = r->request_time;
433 apr_table_mergen(t, "Cache-Control",
434 apr_psprintf(r->pool, "max-age=%" APR_TIME_T_FMT,
435 apr_time_sec(expires - r->request_time)));
436 timestr = apr_palloc(r->pool, APR_RFC822_DATE_LEN);
437 apr_rfc822_date(timestr, expires);
438 apr_table_setn(t, "Expires", timestr);
443 * Output filter to set the Expires response header field
444 * according to the content-type of the response -- if it hasn't
447 static apr_status_t expires_filter(ap_filter_t *f,
448 apr_bucket_brigade *b)
451 expires_dir_config *conf;
456 conf = (expires_dir_config *) ap_get_module_config(r->per_dir_config,
460 * Check to see which output header table we should use;
461 * mod_cgi loads script fields into r->err_headers_out,
464 expiry = apr_table_get(r->err_headers_out, "Expires");
465 if (expiry != NULL) {
466 t = r->err_headers_out;
469 expiry = apr_table_get(r->headers_out, "Expires");
472 if (expiry == NULL) {
474 * No expiration has been set, so we can apply any managed by
475 * this module. First, check to see if there is an applicable
476 * ExpiresByType directive.
478 expiry = apr_table_get(conf->expiresbytype,
479 ap_field_noparam(r->pool, r->content_type));
480 if (expiry == NULL) {
483 * See if we have a wildcard entry for the major type.
485 if (conf->wildcards) {
488 checkmime = apr_pstrdup(r->pool, r->content_type);
489 spos = checkmime ? ap_strchr(checkmime, '/') : NULL;
492 * Without a '/' character, nothing we have will match.
493 * However, we have one.
495 if (strlen(++spos) > 0) {
500 checkmime = apr_pstrcat(r->pool, checkmime, "*", NULL);
502 expiry = apr_table_get(conf->expiresbytype, checkmime);
503 usedefault = (expiry == NULL);
508 * Use the ExpiresDefault directive
510 expiry = conf->expiresdefault;
513 if (expiry != NULL) {
514 set_expiration_fields(r, expiry, t);
517 ap_remove_output_filter(f);
518 return ap_pass_brigade(f->next, b);
521 static void expires_insert_filter(request_rec *r)
523 expires_dir_config *conf;
525 /* Don't add Expires headers to errors */
526 if (ap_is_HTTP_ERROR(r->status)) {
529 /* Say no to subrequests */
530 if (r->main != NULL) {
533 conf = (expires_dir_config *) ap_get_module_config(r->per_dir_config,
536 /* Check to see if the filter is enabled and if there are any applicable
537 * config directives for this directory scope
539 if (conf->active != ACTIVE_ON ||
540 (apr_is_empty_table(conf->expiresbytype) && !conf->expiresdefault)) {
543 ap_add_output_filter("MOD_EXPIRES", NULL, r, r->connection);
546 static void register_hooks(apr_pool_t *p)
548 /* mod_expires needs to run *before* the cache save filter which is
549 * AP_FTYPE_CONTENT_SET-1. Otherwise, our expires won't be honored.
551 ap_register_output_filter("MOD_EXPIRES", expires_filter, NULL,
552 AP_FTYPE_CONTENT_SET-2);
553 ap_hook_insert_error_filter(expires_insert_filter, NULL, NULL, APR_HOOK_MIDDLE);
554 ap_hook_insert_filter(expires_insert_filter, NULL, NULL, APR_HOOK_MIDDLE);
557 module AP_MODULE_DECLARE_DATA expires_module =
559 STANDARD20_MODULE_STUFF,
560 create_dir_expires_config, /* dir config creater */
561 merge_expires_dir_configs, /* dir merger --- default is to override */
562 NULL, /* server config */
563 NULL, /* merge server configs */
564 expires_cmds, /* command apr_table_t */
565 register_hooks /* register hooks */