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apache/httpd/refs/heads/docs-modern-css-2.4/./modules/cache/mod_cache.c
blob: c69fc3932b03d8bd0e4d2d35b5ad78afdc1b19b7 [file]
/* 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 "mod_cache.h"
#include "cache_storage.h"
#include "cache_util.h"
module AP_MODULE_DECLARE_DATA cache_module;
APR_OPTIONAL_FN_TYPE(ap_cache_generate_key) *cache_generate_key;
/* -------------------------------------------------------------- */
/* Handles for cache filters, resolved at startup to eliminate
* a name-to-function mapping on each request
*/
static ap_filter_rec_t *cache_filter_handle;
static ap_filter_rec_t *cache_save_filter_handle;
static ap_filter_rec_t *cache_save_subreq_filter_handle;
static ap_filter_rec_t *cache_out_filter_handle;
static ap_filter_rec_t *cache_out_subreq_filter_handle;
static ap_filter_rec_t *cache_remove_url_filter_handle;
static ap_filter_rec_t *cache_invalidate_filter_handle;
/**
* Entity headers' names
*/
static const char *const MOD_CACHE_ENTITY_HEADERS[] = {
"Allow",
"Content-Encoding",
"Content-Language",
"Content-Length",
"Content-Location",
"Content-MD5",
"Content-Range",
"Content-Type",
"Last-Modified",
NULL
};
/*
* CACHE handler
* -------------
*
* Can we deliver this request from the cache?
* If yes:
* deliver the content by installing the CACHE_OUT filter.
* If no:
* check whether we're allowed to try cache it
* If yes:
* add CACHE_SAVE filter
* If No:
* oh well.
*
* By default, the cache handler runs in the quick handler, bypassing
* virtually all server processing and offering the cache its optimal
* performance. In this mode, the cache bolts onto the front of the
* server, and behaves as a discrete RFC2616 caching proxy
* implementation.
*
* Under certain circumstances, an admin might want to run the cache as
* a normal handler instead of a quick handler, allowing the cache to
* run after the authorisation hooks, or by allowing fine control over
* the placement of the cache in the filter chain. This option comes at
* a performance penalty, and should only be used to achieve specific
* caching goals where the admin understands what they are doing.
*/
static int cache_quick_handler(request_rec *r, int lookup)
{
apr_status_t rv;
const char *auth;
cache_provider_list *providers;
cache_request_rec *cache;
apr_bucket_brigade *out;
apr_bucket *e;
ap_filter_t *next;
ap_filter_rec_t *cache_out_handle;
cache_server_conf *conf;
conf = (cache_server_conf *) ap_get_module_config(r->server->module_config,
&cache_module);
/* only run if the quick handler is enabled */
if (!conf->quick) {
return DECLINED;
}
/*
* Which cache module (if any) should handle this request?
*/
if (!(providers = cache_get_providers(r, conf))) {
return DECLINED;
}
/* make space for the per request config */
cache = apr_pcalloc(r->pool, sizeof(cache_request_rec));
cache->size = -1;
cache->out = apr_brigade_create(r->pool, r->connection->bucket_alloc);
/* save away the possible providers */
cache->providers = providers;
/*
* Are we allowed to serve cached info at all?
*/
if (!ap_cache_check_no_store(cache, r)) {
return DECLINED;
}
/* find certain cache controlling headers */
auth = apr_table_get(r->headers_in, "Authorization");
/* First things first - does the request allow us to return
* cached information at all? If not, just decline the request.
*/
if (auth) {
return DECLINED;
}
/* Are we PUT/POST/DELETE? If so, prepare to invalidate the cached entities.
*/
switch (r->method_number) {
case M_PUT:
case M_POST:
case M_DELETE:
{
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r, APLOGNO(02461)
"PUT/POST/DELETE: Adding CACHE_INVALIDATE filter for %s",
r->uri);
/* Add cache_invalidate filter to this request to force a
* cache entry to be invalidated if the response is
* ultimately successful (2xx).
*/
ap_add_output_filter_handle(
cache_invalidate_filter_handle, cache, r,
r->connection);
return DECLINED;
}
case M_GET: {
break;
}
default : {
ap_log_rerror(
APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r, APLOGNO(02462) "cache: Method '%s' not cacheable by mod_cache, ignoring: %s", r->method, r->uri);
return DECLINED;
}
}
/*
* Try to serve this request from the cache.
*
* If no existing cache file (DECLINED)
* add cache_save filter
* If cached file (OK)
* clear filter stack
* add cache_out filter
* return OK
*/
rv = cache_select(cache, r);
if (rv != OK) {
if (rv == DECLINED) {
if (!lookup) {
/* try to obtain a cache lock at this point. if we succeed,
* we are the first to try and cache this url. if we fail,
* it means someone else is already trying to cache this
* url, and we should just let the request through to the
* backend without any attempt to cache. this stops
* duplicated simultaneous attempts to cache an entity.
*/
rv = cache_try_lock(conf, cache, r);
if (APR_SUCCESS == rv) {
/*
* Add cache_save filter to cache this request. Choose
* the correct filter by checking if we are a subrequest
* or not.
*/
if (r->main) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS,
r, APLOGNO(00749) "Adding CACHE_SAVE_SUBREQ filter for %s",
r->uri);
cache->save_filter = ap_add_output_filter_handle(
cache_save_subreq_filter_handle, cache, r,
r->connection);
}
else {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS,
r, APLOGNO(00750) "Adding CACHE_SAVE filter for %s",
r->uri);
cache->save_filter = ap_add_output_filter_handle(
cache_save_filter_handle, cache, r,
r->connection);
}
apr_pool_userdata_setn(cache, CACHE_CTX_KEY, NULL, r->pool);
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r, APLOGNO(00751)
"Adding CACHE_REMOVE_URL filter for %s",
r->uri);
/* Add cache_remove_url filter to this request to remove a
* stale cache entry if needed. Also put the current cache
* request rec in the filter context, as the request that
* is available later during running the filter may be
* different due to an internal redirect.
*/
cache->remove_url_filter = ap_add_output_filter_handle(
cache_remove_url_filter_handle, cache, r,
r->connection);
}
else {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, rv,
r, APLOGNO(00752) "Cache locked for url, not caching "
"response: %s", r->uri);
/* cache_select() may have added conditional headers */
if (cache->stale_headers) {
r->headers_in = cache->stale_headers;
}
}
}
else {
if (cache->stale_headers) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS,
r, APLOGNO(00753) "Restoring request headers for %s",
r->uri);
r->headers_in = cache->stale_headers;
}
}
}
else {
/* error */
return rv;
}
return DECLINED;
}
/* we've got a cache hit! tell everyone who cares */
cache_run_cache_status(cache->handle, r, r->headers_out, AP_CACHE_HIT,
"cache hit");
/* if we are a lookup, we are exiting soon one way or another; Restore
* the headers. */
if (lookup) {
if (cache->stale_headers) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r, APLOGNO(00754)
"Restoring request headers.");
r->headers_in = cache->stale_headers;
}
}
rv = ap_meets_conditions(r);
if (rv != OK) {
/* If we are a lookup, we have to return DECLINED as we have no
* way of knowing if we will be able to serve the content.
*/
if (lookup) {
return DECLINED;
}
/* Return cached status. */
return rv;
}
/* If we're a lookup, we can exit now instead of serving the content. */
if (lookup) {
return OK;
}
/* Serve up the content */
/* We are in the quick handler hook, which means that no output
* filters have been set. So lets run the insert_filter hook.
*/
ap_run_insert_filter(r);
/*
* Add cache_out filter to serve this request. Choose
* the correct filter by checking if we are a subrequest
* or not.
*/
if (r->main) {
cache_out_handle = cache_out_subreq_filter_handle;
}
else {
cache_out_handle = cache_out_filter_handle;
}
ap_add_output_filter_handle(cache_out_handle, cache, r, r->connection);
/*
* Remove all filters that are before the cache_out filter. This ensures
* that we kick off the filter stack with our cache_out filter being the
* first in the chain. This make sense because we want to restore things
* in the same manner as we saved them.
* There may be filters before our cache_out filter, because
*
* 1. We call ap_set_content_type during cache_select. This causes
* Content-Type specific filters to be added.
* 2. We call the insert_filter hook. This causes filters e.g. like
* the ones set with SetOutputFilter to be added.
*/
next = r->output_filters;
while (next && (next->frec != cache_out_handle)) {
ap_remove_output_filter(next);
next = next->next;
}
/* kick off the filter stack */
out = apr_brigade_create(r->pool, r->connection->bucket_alloc);
e = apr_bucket_eos_create(out->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(out, e);
return ap_pass_brigade_fchk(r, out,
"cache_quick_handler(%s): ap_pass_brigade returned",
cache->provider_name);
}
/**
* If the two filter handles are present within the filter chain, replace
* the last instance of the first filter with the last instance of the
* second filter, and return true. If the second filter is not present at
* all, the first filter is removed, and false is returned. If neither
* filter is present, false is returned and this function does nothing.
* If a stop filter is specified, processing will stop once this filter is
* reached.
*/
static int cache_replace_filter(ap_filter_t *next, ap_filter_rec_t *from,
ap_filter_rec_t *to, ap_filter_rec_t *stop) {
ap_filter_t *ffrom = NULL, *fto = NULL;
while (next && next->frec != stop) {
if (next->frec == from) {
ffrom = next;
}
if (next->frec == to) {
fto = next;
}
next = next->next;
}
if (ffrom && fto) {
ffrom->frec = fto->frec;
ffrom->ctx = fto->ctx;
ap_remove_output_filter(fto);
return 1;
}
if (ffrom) {
ap_remove_output_filter(ffrom);
}
return 0;
}
/**
* Find the given filter, and return it if found, or NULL otherwise.
*/
static ap_filter_t *cache_get_filter(ap_filter_t *next, ap_filter_rec_t *rec) {
while (next) {
if (next->frec == rec && next->ctx) {
break;
}
next = next->next;
}
return next;
}
/**
* The cache handler is functionally similar to the cache_quick_hander,
* however a number of steps that are required by the quick handler are
* not required here, as the normal httpd processing has already handled
* these steps.
*/
static int cache_handler(request_rec *r)
{
apr_status_t rv;
cache_provider_list *providers;
cache_request_rec *cache;
apr_bucket_brigade *out;
apr_bucket *e;
ap_filter_t *next;
ap_filter_rec_t *cache_out_handle;
ap_filter_rec_t *cache_save_handle;
cache_server_conf *conf;
conf = (cache_server_conf *) ap_get_module_config(r->server->module_config,
&cache_module);
/* only run if the quick handler is disabled */
if (conf->quick) {
return DECLINED;
}
/*
* Which cache module (if any) should handle this request?
*/
if (!(providers = cache_get_providers(r, conf))) {
return DECLINED;
}
/* make space for the per request config */
cache = apr_pcalloc(r->pool, sizeof(cache_request_rec));
cache->size = -1;
cache->out = apr_brigade_create(r->pool, r->connection->bucket_alloc);
/* save away the possible providers */
cache->providers = providers;
/*
* Are we allowed to serve cached info at all?
*/
if (!ap_cache_check_no_store(cache, r)) {
return DECLINED;
}
/* Are we PUT/POST/DELETE? If so, prepare to invalidate the cached entities.
*/
switch (r->method_number) {
case M_PUT:
case M_POST:
case M_DELETE:
{
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r, APLOGNO(02463)
"PUT/POST/DELETE: Adding CACHE_INVALIDATE filter for %s",
r->uri);
/* Add cache_invalidate filter to this request to force a
* cache entry to be invalidated if the response is
* ultimately successful (2xx).
*/
ap_add_output_filter_handle(
cache_invalidate_filter_handle, cache, r,
r->connection);
return DECLINED;
}
case M_GET: {
break;
}
default : {
ap_log_rerror(
APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r, APLOGNO(02464) "cache: Method '%s' not cacheable by mod_cache, ignoring: %s", r->method, r->uri);
return DECLINED;
}
}
/*
* Try to serve this request from the cache.
*
* If no existing cache file (DECLINED)
* add cache_save filter
* If cached file (OK)
* clear filter stack
* add cache_out filter
* return OK
*/
rv = cache_select(cache, r);
if (rv != OK) {
if (rv == DECLINED) {
/* try to obtain a cache lock at this point. if we succeed,
* we are the first to try and cache this url. if we fail,
* it means someone else is already trying to cache this
* url, and we should just let the request through to the
* backend without any attempt to cache. this stops
* duplicated simultaneous attempts to cache an entity.
*/
rv = cache_try_lock(conf, cache, r);
if (APR_SUCCESS == rv) {
/*
* Add cache_save filter to cache this request. Choose
* the correct filter by checking if we are a subrequest
* or not.
*/
if (r->main) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS,
r, APLOGNO(00756) "Adding CACHE_SAVE_SUBREQ filter for %s",
r->uri);
cache_save_handle = cache_save_subreq_filter_handle;
}
else {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS,
r, APLOGNO(00757) "Adding CACHE_SAVE filter for %s",
r->uri);
cache_save_handle = cache_save_filter_handle;
}
ap_add_output_filter_handle(cache_save_handle, cache, r,
r->connection);
/*
* Did the user indicate the precise location of the
* CACHE_SAVE filter by inserting the CACHE filter as a
* marker?
*
* If so, we get cunning and replace CACHE with the
* CACHE_SAVE filter. This has the effect of inserting
* the CACHE_SAVE filter at the precise location where
* the admin wants to cache the content. All filters that
* lie before and after the original location of the CACHE
* filter will remain in place.
*/
if (cache_replace_filter(r->output_filters,
cache_filter_handle, cache_save_handle,
ap_get_input_filter_handle("SUBREQ_CORE"))) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS,
r, APLOGNO(00758) "Replacing CACHE with CACHE_SAVE "
"filter for %s", r->uri);
}
/* save away the save filter stack */
cache->save_filter = cache_get_filter(r->output_filters,
cache_save_filter_handle);
apr_pool_userdata_setn(cache, CACHE_CTX_KEY, NULL, r->pool);
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r, APLOGNO(00759)
"Adding CACHE_REMOVE_URL filter for %s",
r->uri);
/* Add cache_remove_url filter to this request to remove a
* stale cache entry if needed. Also put the current cache
* request rec in the filter context, as the request that
* is available later during running the filter may be
* different due to an internal redirect.
*/
cache->remove_url_filter
= ap_add_output_filter_handle(
cache_remove_url_filter_handle, cache, r,
r->connection);
}
else {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, rv,
r, APLOGNO(00760) "Cache locked for url, not caching "
"response: %s", r->uri);
}
}
else {
/* error */
return rv;
}
return DECLINED;
}
/* we've got a cache hit! tell everyone who cares */
cache_run_cache_status(cache->handle, r, r->headers_out, AP_CACHE_HIT,
"cache hit");
rv = ap_meets_conditions(r);
if (rv != OK) {
return rv;
}
/* Serve up the content */
/*
* Add cache_out filter to serve this request. Choose
* the correct filter by checking if we are a subrequest
* or not.
*/
if (r->main) {
cache_out_handle = cache_out_subreq_filter_handle;
}
else {
cache_out_handle = cache_out_filter_handle;
}
ap_add_output_filter_handle(cache_out_handle, cache, r, r->connection);
/*
* Did the user indicate the precise location of the CACHE_OUT filter by
* inserting the CACHE filter as a marker?
*
* If so, we get cunning and replace CACHE with the CACHE_OUT filters.
* This has the effect of inserting the CACHE_OUT filter at the precise
* location where the admin wants to cache the content. All filters that
* lie *after* the original location of the CACHE filter will remain in
* place.
*/
if (cache_replace_filter(r->output_filters, cache_filter_handle,
cache_out_handle, ap_get_input_filter_handle("SUBREQ_CORE"))) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS,
r, APLOGNO(00761) "Replacing CACHE with CACHE_OUT filter for %s",
r->uri);
}
/*
* Remove all filters that are before the cache_out filter. This ensures
* that we kick off the filter stack with our cache_out filter being the
* first in the chain. This make sense because we want to restore things
* in the same manner as we saved them.
* There may be filters before our cache_out filter, because
*
* 1. We call ap_set_content_type during cache_select. This causes
* Content-Type specific filters to be added.
* 2. We call the insert_filter hook. This causes filters e.g. like
* the ones set with SetOutputFilter to be added.
*/
next = r->output_filters;
while (next && (next->frec != cache_out_handle)) {
ap_remove_output_filter(next);
next = next->next;
}
/* kick off the filter stack */
out = apr_brigade_create(r->pool, r->connection->bucket_alloc);
e = apr_bucket_eos_create(out->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(out, e);
return ap_pass_brigade_fchk(r, out, "cache(%s): ap_pass_brigade returned",
cache->provider_name);
}
/*
* CACHE_OUT filter
* ----------------
*
* Deliver cached content (headers and body) up the stack.
*/
static apr_status_t cache_out_filter(ap_filter_t *f, apr_bucket_brigade *in)
{
request_rec *r = f->r;
cache_request_rec *cache = (cache_request_rec *)f->ctx;
if (!cache) {
/* user likely configured CACHE_OUT manually; they should use mod_cache
* configuration to do that */
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00762)
"CACHE/CACHE_OUT filter enabled while caching is disabled, ignoring");
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, in);
}
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r, APLOGNO(00763)
"cache: running CACHE_OUT filter");
/* clean out any previous response up to EOS, if any */
while (!APR_BRIGADE_EMPTY(in)) {
apr_bucket *e = APR_BRIGADE_FIRST(in);
if (APR_BUCKET_IS_EOS(e)) {
apr_bucket_brigade *bb = apr_brigade_create(r->pool,
r->connection->bucket_alloc);
/* restore content type of cached response if available */
/* Needed especially when stale content gets served. */
const char *ct = apr_table_get(cache->handle->resp_hdrs, "Content-Type");
if (ct) {
ap_set_content_type(r, ct);
}
/* restore status of cached response */
r->status = cache->handle->cache_obj->info.status;
/* recall_headers() was called in cache_select() */
cache->provider->recall_body(cache->handle, r->pool, bb);
APR_BRIGADE_PREPEND(in, bb);
/* This filter is done once it has served up its content */
ap_remove_output_filter(f);
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r, APLOGNO(00764)
"cache: serving %s", r->uri);
return ap_pass_brigade(f->next, in);
}
apr_bucket_delete(e);
}
return APR_SUCCESS;
}
/*
* Having jumped through all the hoops and decided to cache the
* response, call store_body() for each brigade, handling the
* case where the provider can't swallow the full brigade. In this
* case, we write the brigade we were passed out downstream, and
* loop around to try and cache some more until the in brigade is
* completely empty. As soon as the out brigade contains eos, call
* commit_entity() to finalise the cached element.
*/
static int cache_save_store(ap_filter_t *f, apr_bucket_brigade *in,
cache_server_conf *conf, cache_request_rec *cache)
{
int rv = APR_SUCCESS;
apr_bucket *e;
/* pass the brigade in into the cache provider, which is then
* expected to move cached buckets to the out brigade, for us
* to pass up the filter stack. repeat until in is empty, or
* we fail.
*/
while (APR_SUCCESS == rv && !APR_BRIGADE_EMPTY(in)) {
rv = cache->provider->store_body(cache->handle, f->r, in, cache->out);
if (rv != APR_SUCCESS) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, rv, f->r, APLOGNO(00765)
"cache: Cache provider's store_body failed for URI %s", f->r->uri);
ap_remove_output_filter(f);
/* give someone else the chance to cache the file */
cache_remove_lock(conf, cache, f->r, NULL);
/* give up trying to cache, just step out the way */
APR_BRIGADE_PREPEND(in, cache->out);
return ap_pass_brigade(f->next, in);
}
/* does the out brigade contain eos? if so, we're done, commit! */
for (e = APR_BRIGADE_FIRST(cache->out);
e != APR_BRIGADE_SENTINEL(cache->out);
e = APR_BUCKET_NEXT(e))
{
if (APR_BUCKET_IS_EOS(e)) {
rv = cache->provider->commit_entity(cache->handle, f->r);
break;
}
}
/* conditionally remove the lock as soon as we see the eos bucket */
cache_remove_lock(conf, cache, f->r, cache->out);
if (APR_BRIGADE_EMPTY(cache->out)) {
if (APR_BRIGADE_EMPTY(in)) {
/* cache provider wants more data before passing the brigade
* upstream, oblige the provider by leaving to fetch more.
*/
break;
}
else {
/* oops, no data out, but not all data read in either, be
* safe and stand down to prevent a spin.
*/
ap_log_rerror(APLOG_MARK, APLOG_WARNING, rv, f->r, APLOGNO(00766)
"cache: Cache provider's store_body returned an "
"empty brigade, but didn't consume all of the "
"input brigade, standing down to prevent a spin");
ap_remove_output_filter(f);
/* give someone else the chance to cache the file */
cache_remove_lock(conf, cache, f->r, NULL);
return ap_pass_brigade(f->next, in);
}
}
rv = ap_pass_brigade(f->next, cache->out);
}
return rv;
}
/**
* Sanity check for 304 Not Modified responses, as per RFC2616 Section 10.3.5.
*/
static int cache_header_cmp(apr_pool_t *pool, apr_table_t *left,
apr_table_t *right, const char *key)
{
const char *h1, *h2;
if ((h1 = cache_table_getm(pool, left, key))
&& (h2 = cache_table_getm(pool, right, key)) && (strcmp(h1, h2))) {
return 1;
}
return 0;
}
/*
* CACHE_SAVE filter
* ---------------
*
* Decide whether or not this content should be cached.
* If we decide no it should not:
* remove the filter from the chain
* If we decide yes it should:
* Have we already started saving the response?
* If we have started, pass the data to the storage manager via store_body
* Otherwise:
* Check to see if we *can* save this particular response.
* If we can, call cache_create_entity() and save the headers and body
* Finally, pass the data to the next filter (the network or whatever)
*
* After the various failure cases, the cache lock is proactively removed, so
* that another request is given the opportunity to attempt to cache without
* waiting for a potentially slow client to acknowledge the failure.
*/
static apr_status_t cache_save_filter(ap_filter_t *f, apr_bucket_brigade *in)
{
int rv = !OK;
request_rec *r = f->r;
cache_request_rec *cache = (cache_request_rec *)f->ctx;
cache_server_conf *conf;
cache_dir_conf *dconf;
cache_control_t control;
const char *cc_out, *cl, *pragma;
const char *exps, *lastmods, *dates, *etag;
apr_time_t exp, date, lastmod, now;
apr_off_t size = -1;
cache_info *info = NULL;
const char *reason, *const *eh;
apr_pool_t *p;
apr_bucket *e;
apr_table_t *headers;
const char *query;
conf = (cache_server_conf *) ap_get_module_config(r->server->module_config,
&cache_module);
/* Setup cache_request_rec */
if (!cache) {
/* user likely configured CACHE_SAVE manually; they should really use
* mod_cache configuration to do that
*/
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00767)
"CACHE/CACHE_SAVE filter enabled while caching is disabled, ignoring");
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, in);
}
reason = NULL;
p = r->pool;
/*
* Pass Data to Cache
* ------------------
* This section passes the brigades into the cache modules, but only
* if the setup section (see below) is complete.
*/
if (cache->block_response) {
/* We've already sent down the response and EOS. So, ignore
* whatever comes now.
*/
return APR_SUCCESS;
}
/* have we already run the cacheability check and set up the
* cached file handle?
*/
if (cache->in_checked) {
return cache_save_store(f, in, conf, cache);
}
/*
* Setup Data in Cache
* -------------------
* This section opens the cache entity and sets various caching
* parameters, and decides whether this URL should be cached at
* all. This section is* run before the above section.
*/
dconf = ap_get_module_config(r->per_dir_config, &cache_module);
/* RFC2616 13.8 Errors or Incomplete Response Cache Behavior:
* If a cache receives a 5xx response while attempting to revalidate an
* entry, it MAY either forward this response to the requesting client,
* or act as if the server failed to respond. In the latter case, it MAY
* return a previously received response unless the cached entry
* includes the "must-revalidate" cache-control directive (see section
* 14.9).
*
* This covers the case where an error was generated behind us, for example
* by a backend server via mod_proxy.
*/
if (dconf->stale_on_error && r->status >= HTTP_INTERNAL_SERVER_ERROR) {
ap_remove_output_filter(cache->remove_url_filter);
if (cache->stale_handle
&& !cache->stale_handle->cache_obj->info.control.must_revalidate
&& !cache->stale_handle->cache_obj->info.control.proxy_revalidate) {
const char *warn_head;
/* morph the current save filter into the out filter, and serve from
* cache.
*/
cache->handle = cache->stale_handle;
if (r->main) {
f->frec = cache_out_subreq_filter_handle;
}
else {
f->frec = cache_out_filter_handle;
}
r->headers_out = cache->stale_handle->resp_hdrs;
ap_set_content_type(r, apr_table_get(
cache->stale_handle->resp_hdrs, "Content-Type"));
/* add a revalidation warning */
warn_head = apr_table_get(r->err_headers_out, "Warning");
if ((warn_head == NULL) || ((warn_head != NULL)
&& (ap_strstr_c(warn_head, "111") == NULL))) {
apr_table_mergen(r->err_headers_out, "Warning",
"111 Revalidation failed");
}
cache_run_cache_status(cache->handle, r, r->headers_out, AP_CACHE_HIT,
apr_psprintf(r->pool,
"cache hit: %d status; stale content returned",
r->status));
/* give someone else the chance to cache the file */
cache_remove_lock(conf, cache, f->r, NULL);
/* pass brigade to our morphed out filter */
return ap_pass_brigade(f, in);
}
}
query = cache_use_early_url(r) ? r->parsed_uri.query : r->args;
/* read expiry date; if a bad date, then leave it so the client can
* read it
*/
exps = apr_table_get(r->err_headers_out, "Expires");
if (exps == NULL) {
exps = apr_table_get(r->headers_out, "Expires");
}
if (exps != NULL) {
exp = apr_date_parse_http(exps);
}
else {
exp = APR_DATE_BAD;
}
/* read the last-modified date; if the date is bad, then delete it */
lastmods = apr_table_get(r->err_headers_out, "Last-Modified");
if (lastmods == NULL) {
lastmods = apr_table_get(r->headers_out, "Last-Modified");
}
if (lastmods != NULL) {
lastmod = apr_date_parse_http(lastmods);
if (lastmod == APR_DATE_BAD) {
lastmods = NULL;
}
}
else {
lastmod = APR_DATE_BAD;
}
/* read the etag and cache-control from the entity */
etag = apr_table_get(r->err_headers_out, "Etag");
if (etag == NULL) {
etag = apr_table_get(r->headers_out, "Etag");
}
cc_out = cache_table_getm(r->pool, r->err_headers_out, "Cache-Control");
pragma = cache_table_getm(r->pool, r->err_headers_out, "Pragma");
headers = r->err_headers_out;
if (!cc_out && !pragma) {
cc_out = cache_table_getm(r->pool, r->headers_out, "Cache-Control");
pragma = cache_table_getm(r->pool, r->headers_out, "Pragma");
headers = r->headers_out;
}
/* Have we received a 304 response without any headers at all? Fall back to
* the original headers in the original cached request.
*/
if (r->status == HTTP_NOT_MODIFIED && cache->stale_handle) {
if (!cc_out && !pragma) {
cc_out = cache_table_getm(r->pool, cache->stale_handle->resp_hdrs,
"Cache-Control");
pragma = cache_table_getm(r->pool, cache->stale_handle->resp_hdrs,
"Pragma");
}
/* 304 does not contain Content-Type and mod_mime regenerates the
* Content-Type based on the r->filename. This would lead to original
* Content-Type to be lost (overwritten by whatever mod_mime generates).
* We preserves the original Content-Type here. */
ap_set_content_type(r, apr_table_get(
cache->stale_handle->resp_hdrs, "Content-Type"));
}
/* Parse the cache control header */
memset(&control, 0, sizeof(cache_control_t));
ap_cache_control(r, &control, cc_out, pragma, headers);
/*
* what responses should we not cache?
*
* At this point we decide based on the response headers whether it
* is appropriate _NOT_ to cache the data from the server. There are
* a whole lot of conditions that prevent us from caching this data.
* They are tested here one by one to be clear and unambiguous.
*/
if (r->status != HTTP_OK && r->status != HTTP_NON_AUTHORITATIVE
&& r->status != HTTP_PARTIAL_CONTENT
&& r->status != HTTP_MULTIPLE_CHOICES
&& r->status != HTTP_MOVED_PERMANENTLY
&& r->status != HTTP_NOT_MODIFIED) {
/* RFC2616 13.4 we are allowed to cache 200, 203, 206, 300, 301 or 410
* We allow the caching of 206, but a cache implementation might choose
* to decline to cache a 206 if it doesn't know how to.
* We include 304 Not Modified here too as this is the origin server
* telling us to serve the cached copy.
*/
if (exps != NULL || cc_out != NULL) {
/* We are also allowed to cache any response given that it has a
* valid Expires or Cache Control header. If we find a either of
* those here, we pass request through the rest of the tests. From
* the RFC:
*
* A response received with any other status code (e.g. status
* codes 302 and 307) MUST NOT be returned in a reply to a
* subsequent request unless there are cache-control directives or
* another header(s) that explicitly allow it. For example, these
* include the following: an Expires header (section 14.21); a
* "max-age", "s-maxage", "must-revalidate", "proxy-revalidate",
* "public" or "private" cache-control directive (section 14.9).
*
* FIXME: Wrong if cc_out has just an extension we don't know about
*/
}
else {
reason = apr_psprintf(p, "Response status %d", r->status);
}
}
if (reason) {
/* noop */
}
else if (!control.s_maxage && !control.max_age && !dconf->store_expired
&& exps != NULL && exp == APR_DATE_BAD) {
/* if a broken Expires header is present, don't cache it
* Unless CC: s-maxage or max-age is present
*/
reason = apr_pstrcat(p, "Broken expires header: ", exps, NULL);
}
else if (!control.s_maxage && !control.max_age
&& !dconf->store_expired && exp != APR_DATE_BAD
&& exp < r->request_time) {
/* if a Expires header is in the past, don't cache it
* Unless CC: s-maxage or max-age is present
*/
reason = "Expires header already expired; not cacheable";
}
else if (!dconf->store_expired && (control.must_revalidate
|| control.proxy_revalidate) && (!control.s_maxage_value
|| (!control.s_maxage && !control.max_age_value)) && lastmods
== NULL && etag == NULL) {
/* if we're already stale, but can never revalidate, don't cache it */
reason
= "s-maxage or max-age zero and no Last-Modified or Etag; not cacheable";
}
else if (!conf->ignorequerystring && query && exps == NULL
&& !control.max_age && !control.s_maxage) {
/* if a query string is present but no explicit expiration time,
* don't cache it (RFC 2616/13.9 & 13.2.1)
*/
reason = "Query string present but no explicit expiration time";
}
else if (r->status == HTTP_NOT_MODIFIED &&
!cache->handle && !cache->stale_handle) {
/* if the server said 304 Not Modified but we have no cache
* file - pass this untouched to the user agent, it's not for us.
*/
reason = "HTTP Status 304 Not Modified";
}
else if (r->status == HTTP_OK && lastmods == NULL && etag == NULL && (exps
== NULL) && (dconf->no_last_mod_ignore == 0) && !control.max_age
&& !control.s_maxage) {
/* 200 OK response from HTTP/1.0 and up without Last-Modified,
* Etag, Expires, Cache-Control:max-age, or Cache-Control:s-maxage
* headers.
*/
/* Note: mod-include clears last_modified/expires/etags - this
* is why we have an optional function for a key-gen ;-)
*/
reason = "No Last-Modified; Etag; Expires; Cache-Control:max-age or Cache-Control:s-maxage headers";
}
else if (!dconf->store_nostore && control.no_store) {
/* RFC2616 14.9.2 Cache-Control: no-store response
* indicating do not cache, or stop now if you are
* trying to cache it.
*/
reason = "Cache-Control: no-store present";
}
else if (!dconf->store_private && control.private) {
/* RFC2616 14.9.1 Cache-Control: private response
* this object is marked for this user's eyes only. Behave
* as a tunnel.
*/
reason = "Cache-Control: private present";
}
else if (apr_table_get(r->headers_in, "Authorization")
&& !(control.s_maxage || control.must_revalidate
|| control.proxy_revalidate || control.public)) {
/* RFC2616 14.8 Authorisation:
* if authorisation is included in the request, we don't cache,
* but we can cache if the following exceptions are true:
* 1) If Cache-Control: s-maxage is included
* 2) If Cache-Control: must-revalidate is included
* 3) If Cache-Control: public is included
*/
reason = "Authorization required";
}
else if (ap_find_token(NULL, apr_table_get(r->headers_out, "Vary"), "*")) {
reason = "Vary header contains '*'";
}
else if (apr_table_get(r->subprocess_env, "no-cache") != NULL) {
reason = "environment variable 'no-cache' is set";
}
else if (r->no_cache) {
/* or we've been asked not to cache it above */
reason = "r->no_cache present";
}
else if (cache->stale_handle
&& APR_DATE_BAD
!= (date = apr_date_parse_http(
apr_table_get(r->headers_out, "Date")))
&& date < cache->stale_handle->cache_obj->info.date) {
/**
* 13.12 Cache Replacement:
*
* Note: a new response that has an older Date header value than
* existing cached responses is not cacheable.
*/
reason = "updated entity is older than cached entity";
/* while this response is not cacheable, the previous response still is */
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02474)
"cache: Removing CACHE_REMOVE_URL filter.");
ap_remove_output_filter(cache->remove_url_filter);
}
else if (r->status == HTTP_NOT_MODIFIED && cache->stale_handle) {
apr_table_t *left = cache->stale_handle->resp_hdrs;
apr_table_t *right = r->headers_out;
const char *ehs = NULL;
/* and lastly, contradiction checks for revalidated responses
* as per RFC2616 Section 10.3.5
*/
if (cache_header_cmp(r->pool, left, right, "ETag")) {
ehs = "ETag";
}
for (eh = MOD_CACHE_ENTITY_HEADERS; *eh; ++eh) {
if (cache_header_cmp(r->pool, left, right, *eh)) {
ehs = (ehs) ? apr_pstrcat(r->pool, ehs, ", ", *eh, NULL) : *eh;
}
}
if (ehs) {
reason = apr_pstrcat(r->pool, "contradiction: 304 Not Modified; "
"but ", ehs, " modified", NULL);
}
}
/**
* Enforce RFC2616 Section 10.3.5, just in case. We caught any
* inconsistencies above.
*
* If the conditional GET used a strong cache validator (see section
* 13.3.3), the response SHOULD NOT include other entity-headers.
* Otherwise (i.e., the conditional GET used a weak validator), the
* response MUST NOT include other entity-headers; this prevents
* inconsistencies between cached entity-bodies and updated headers.
*/
if (r->status == HTTP_NOT_MODIFIED) {
for (eh = MOD_CACHE_ENTITY_HEADERS; *eh; ++eh) {
apr_table_unset(r->headers_out, *eh);
}
}
/* Hold the phone. Some servers might allow us to cache a 2xx, but
* then make their 304 responses non cacheable. RFC2616 says this:
*
* If a 304 response indicates an entity not currently cached, then
* the cache MUST disregard the response and repeat the request
* without the conditional.
*
* A 304 response with contradictory headers is technically a
* different entity, to be safe, we remove the entity from the cache.
*/
if (reason && r->status == HTTP_NOT_MODIFIED && cache->stale_handle) {
ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(02473)
"cache: %s responded with an uncacheable 304, "
"retrying the request %s. Reason: %s",
cache->key, r->unparsed_uri, reason);
/* we've got a cache conditional miss! tell anyone who cares */
cache_run_cache_status(cache->handle, r, r->headers_out, AP_CACHE_MISS,
apr_psprintf(r->pool,
"conditional cache miss: 304 was uncacheable, entity removed: %s",
reason));
/* remove the cached entity immediately, we might cache it again */
ap_remove_output_filter(cache->remove_url_filter);
cache_remove_url(cache, r);
/* let someone else attempt to cache */
cache_remove_lock(conf, cache, r, NULL);
/* remove this filter from the chain */
ap_remove_output_filter(f);
/* retry without the conditionals */
apr_table_unset(r->headers_in, "If-Match");
apr_table_unset(r->headers_in, "If-Modified-Since");
apr_table_unset(r->headers_in, "If-None-Match");
apr_table_unset(r->headers_in, "If-Range");
apr_table_unset(r->headers_in, "If-Unmodified-Since");
/* Currently HTTP_NOT_MODIFIED, and after the redirect, handlers won't think to set status to HTTP_OK */
r->status = HTTP_OK;
ap_internal_redirect(r->unparsed_uri, r);
return APR_SUCCESS;
}
/* Set the content length if known.
*/
cl = apr_table_get(r->err_headers_out, "Content-Length");
if (cl == NULL) {
cl = apr_table_get(r->headers_out, "Content-Length");
}
if (cl && !ap_parse_strict_length(&size, cl)) {
reason = "invalid content length";
}
if (reason) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00768)
"cache: %s not cached for request %s. Reason: %s",
cache->key, r->unparsed_uri, reason);
/* we've got a cache miss! tell anyone who cares */
cache_run_cache_status(cache->handle, r, r->headers_out, AP_CACHE_MISS,
reason);
/* remove this filter from the chain */
ap_remove_output_filter(f);
/* remove the lock file unconditionally */
cache_remove_lock(conf, cache, r, NULL);
/* ship the data up the stack */
return ap_pass_brigade(f->next, in);
}
/* Make it so that we don't execute this path again. */
cache->in_checked = 1;
if (!cl) {
/* if we don't get the content-length, see if we have all the
* buckets and use their length to calculate the size
*/
int all_buckets_here=0;
size=0;
for (e = APR_BRIGADE_FIRST(in);
e != APR_BRIGADE_SENTINEL(in);
e = APR_BUCKET_NEXT(e))
{
if (APR_BUCKET_IS_EOS(e)) {
all_buckets_here=1;
break;
}
if (APR_BUCKET_IS_FLUSH(e)) {
continue;
}
if (e->length == (apr_size_t)-1) {
break;
}
size += e->length;
}
if (!all_buckets_here) {
size = -1;
}
}
/* remember content length to check response size against later */
cache->size = size;
/* It's safe to cache the response.
*
* There are two possibilities at this point:
* - cache->handle == NULL. In this case there is no previously
* cached entity anywhere on the system. We must create a brand
* new entity and store the response in it.
* - cache->stale_handle != NULL. In this case there is a stale
* entity in the system which needs to be replaced by new
* content (unless the result was 304 Not Modified, which means
* the cached entity is actually fresh, and we should update
* the headers).
*/
/* Did we have a stale cache entry that really is stale?
*/
if (cache->stale_handle) {
if (r->status == HTTP_NOT_MODIFIED) {
/* Oh, hey. It isn't that stale! Yay! */
cache->handle = cache->stale_handle;
info = &cache->handle->cache_obj->info;
rv = OK;
}
else {
/* Oh, well. Toss it. */
cache->provider->remove_entity(cache->stale_handle);
/* Treat the request as if it wasn't conditional. */
cache->stale_handle = NULL;
/*
* Restore the original request headers as they may be needed
* by further output filters like the byterange filter to make
* the correct decisions.
*/
r->headers_in = cache->stale_headers;
}
}
/* no cache handle, create a new entity */
if (!cache->handle) {
rv = cache_create_entity(cache, r, size, in);
info = apr_pcalloc(r->pool, sizeof(cache_info));
/* We only set info->status upon the initial creation. */
info->status = r->status;
}
if (rv != OK) {
/* we've got a cache miss! tell anyone who cares */
cache_run_cache_status(cache->handle, r, r->headers_out, AP_CACHE_MISS,
"cache miss: cache unwilling to store response");
/* Caching layer declined the opportunity to cache the response */
ap_remove_output_filter(f);
cache_remove_lock(conf, cache, r, NULL);
return ap_pass_brigade(f->next, in);
}
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00769)
"cache: Caching url %s for request %s",
cache->key, r->unparsed_uri);
/* We are actually caching this response. So it does not
* make sense to remove this entity any more.
*/
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00770)
"cache: Removing CACHE_REMOVE_URL filter.");
ap_remove_output_filter(cache->remove_url_filter);
/*
* We now want to update the cache file header information with
* the new date, last modified, expire and content length and write
* it away to our cache file. First, we determine these values from
* the response, using heuristics if appropriate.
*
* In addition, we make HTTP/1.1 age calculations and write them away
* too.
*/
/* store away the previously parsed cache control headers */
memcpy(&info->control, &control, sizeof(cache_control_t));
/* Read the date. Generate one if one is not supplied */
dates = apr_table_get(r->err_headers_out, "Date");
if (dates == NULL) {
dates = apr_table_get(r->headers_out, "Date");
}
if (dates != NULL) {
info->date = apr_date_parse_http(dates);
}
else {
info->date = APR_DATE_BAD;
}
now = apr_time_now();
if (info->date == APR_DATE_BAD) { /* No, or bad date */
/* no date header (or bad header)! */
info->date = now;
}
date = info->date;
/* set response_time for HTTP/1.1 age calculations */
info->response_time = now;
/* get the request time */
info->request_time = r->request_time;
/* check last-modified date */
if (lastmod != APR_DATE_BAD && lastmod > date) {
/* if it's in the future, then replace by date */
lastmod = date;
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0,
r, APLOGNO(00771) "cache: Last modified is in the future, "
"replacing with now");
}
/* CC has priority over Expires. */
if (control.s_maxage || control.max_age) {
apr_int64_t x;
x = control.s_maxage ? control.s_maxage_value : control.max_age_value;
x = x * MSEC_ONE_SEC;
if (x < dconf->minex) {
x = dconf->minex;
}
if (x > dconf->maxex) {
x = dconf->maxex;
}
exp = date + x;
}
/* if no expiry date then
* if Cache-Control: s-maxage
* expiry date = date + smaxage
* if Cache-Control: max-age
* expiry date = date + max-age
* else if lastmod
* expiry date = date + min((date - lastmod) * factor, maxexpire)
* else
* expire date = date + defaultexpire
*/
if (exp == APR_DATE_BAD) {
if ((lastmod != APR_DATE_BAD) && (lastmod < date)) {
/* if lastmod == date then you get 0*conf->factor which results in
* an expiration time of now. This causes some problems with
* freshness calculations, so we choose the else path...
*/
apr_time_t x = (apr_time_t) ((date - lastmod) * dconf->factor);
if (x < dconf->minex) {
x = dconf->minex;
}
if (x > dconf->maxex) {
x = dconf->maxex;
}
exp = date + x;
}
else {
exp = date + dconf->defex;
}
}
info->expire = exp;
/* We found a stale entry which wasn't really stale. */
if (cache->stale_handle) {
/* RFC 2616 10.3.5 states that entity headers are not supposed
* to be in the 304 response. Therefore, we need to combine the
* response headers with the cached headers *before* we update
* the cached headers.
*
* However, before doing that, we need to first merge in
* err_headers_out (note that store_headers() below already selects
* the cacheable only headers using ap_cache_cacheable_headers_out(),
* here we want to keep the original headers in r->headers_out and
* forward all of them to the client, including non-cacheable ones).
*/
r->headers_out = cache_merge_headers_out(r);
apr_table_clear(r->err_headers_out);
/* Merge in our cached headers. However, keep any updated values. */
/* take output, overlay on top of cached */
cache_accept_headers(cache->handle, r, r->headers_out,
cache->handle->resp_hdrs, 1);
}
/* Write away header information to cache. It is possible that we are
* trying to update headers for an entity which has already been cached.
*
* This may fail, due to an unwritable cache area. E.g. filesystem full,
* permissions problems or a read-only (re)mount. This must be handled
* later.
*/
rv = cache->provider->store_headers(cache->handle, r, info);
/* Did we just update the cached headers on a revalidated response?
*
* If so, we can now decide what to serve to the client. This is done in
* the same way as with a regular response, but conditions are now checked
* against the cached or merged response headers.
*/
if (cache->stale_handle) {
apr_bucket_brigade *bb;
apr_bucket *bkt;
int status;
/* Load in the saved status and clear the status line. */
r->status = info->status;
r->status_line = NULL;
/* We're just saving response headers, so we are done. Commit
* the response at this point, unless there was a previous error.
*/
if (rv == APR_SUCCESS) {
rv = cache->provider->commit_entity(cache->handle, r);
}
bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
/* Restore the original request headers and see if we need to
* return anything else than the cached response (ie. the original
* request was conditional).
*/
r->headers_in = cache->stale_headers;
status = ap_meets_conditions(r);
if (status != OK) {
r->status = status;
/* Strip the entity headers merged from the cached headers before
* updating the entry (see cache_accept_headers() above).
*/
for (eh = MOD_CACHE_ENTITY_HEADERS; *eh; ++eh) {
apr_table_unset(r->headers_out, *eh);
}
bkt = apr_bucket_flush_create(bb->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(bb, bkt);
}
else {
cache->provider->recall_body(cache->handle, r->pool, bb);
bkt = apr_bucket_eos_create(bb->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(bb, bkt);
}
cache->block_response = 1;
/* Before returning we need to handle the possible case of an
* unwritable cache. Rather than leaving the entity in the cache
* and having it constantly re-validated, now that we have recalled
* the body it is safe to try and remove the url from the cache.
*/
if (rv != APR_SUCCESS) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, rv, r, APLOGNO(00772)
"cache: updating headers with store_headers failed. "
"Removing cached url.");
rv = cache->provider->remove_url(cache->stale_handle, r);
if (rv != OK) {
/* Probably a mod_cache_disk cache area has been (re)mounted
* read-only, or that there is a permissions problem.
*/
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, rv, r, APLOGNO(00773)
"cache: attempt to remove url from cache unsuccessful.");
}
/* we've got a cache conditional hit! tell anyone who cares */
cache_run_cache_status(cache->handle, r, r->headers_out,
AP_CACHE_REVALIDATE,
"conditional cache hit: entity refresh failed");
}
else {
/* we've got a cache conditional hit! tell anyone who cares */
cache_run_cache_status(cache->handle, r, r->headers_out,
AP_CACHE_REVALIDATE,
"conditional cache hit: entity refreshed");
}
/* let someone else attempt to cache */
cache_remove_lock(conf, cache, r, NULL);
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r, APLOGNO(02971)
"cache: serving %s (revalidated)", r->uri);
return ap_pass_brigade(f->next, bb);
}
if (rv != APR_SUCCESS) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, rv, r, APLOGNO(00774)
"cache: store_headers failed");
/* we've got a cache miss! tell anyone who cares */
cache_run_cache_status(cache->handle, r, r->headers_out, AP_CACHE_MISS,
"cache miss: store_headers failed");
ap_remove_output_filter(f);
cache_remove_lock(conf, cache, r, NULL);
return ap_pass_brigade(f->next, in);
}
/* we've got a cache miss! tell anyone who cares */
cache_run_cache_status(cache->handle, r, r->headers_out, AP_CACHE_MISS,
"cache miss: attempting entity save");
return cache_save_store(f, in, conf, cache);
}
/*
* CACHE_REMOVE_URL filter
* -----------------------
*
* This filter gets added in the quick handler every time the CACHE_SAVE filter
* gets inserted. Its purpose is to remove a confirmed stale cache entry from
* the cache.
*
* CACHE_REMOVE_URL has to be a protocol filter to ensure that is run even if
* the response is a canned error message, which removes the content filters
* and thus the CACHE_SAVE filter from the chain.
*
* CACHE_REMOVE_URL expects cache request rec within its context because the
* request this filter runs on can be different from the one whose cache entry
* should be removed, due to internal redirects.
*
* Note that CACHE_SAVE_URL (as a content-set filter, hence run before the
* protocol filters) will remove this filter if it decides to cache the file.
* Therefore, if this filter is left in, it must mean we need to toss any
* existing files.
*/
static apr_status_t cache_remove_url_filter(ap_filter_t *f,
apr_bucket_brigade *in)
{
request_rec *r = f->r;
cache_request_rec *cache;
/* Setup cache_request_rec */
cache = (cache_request_rec *) f->ctx;
if (!cache) {
/* user likely configured CACHE_REMOVE_URL manually; they should really
* use mod_cache configuration to do that. So:
* 1. Remove ourselves
* 2. Do nothing and bail out
*/
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00775)
"cache: CACHE_REMOVE_URL enabled unexpectedly");
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, in);
}
/* Now remove this cache entry from the cache */
cache_remove_url(cache, r);
/* remove ourselves */
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, in);
}
/*
* CACHE_INVALIDATE filter
* -----------------------
*
* This filter gets added in the quick handler should a PUT, POST or DELETE
* method be detected. If the response is successful, we must invalidate any
* cached entity as per RFC2616 section 13.10.
*
* CACHE_INVALIDATE has to be a protocol filter to ensure that is run even if
* the response is a canned error message, which removes the content filters
* from the chain.
*
* CACHE_INVALIDATE expects cache request rec within its context because the
* request this filter runs on can be different from the one whose cache entry
* should be removed, due to internal redirects.
*/
static apr_status_t cache_invalidate_filter(ap_filter_t *f,
apr_bucket_brigade *in)
{
request_rec *r = f->r;
cache_request_rec *cache;
/* Setup cache_request_rec */
cache = (cache_request_rec *) f->ctx;
if (!cache) {
/* user likely configured CACHE_INVALIDATE manually; they should really
* use mod_cache configuration to do that. So:
* 1. Remove ourselves
* 2. Do nothing and bail out
*/
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02465)
"cache: CACHE_INVALIDATE enabled unexpectedly: %s", r->uri);
}
else {
if (r->status >= HTTP_MULTIPLE_CHOICES) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02466)
"cache: response status to '%s' method is %d (>=HTTP_MULTIPLE_CHOICES), not invalidating cached entity: %s", r->method, r->status, r->uri);
}
else {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r, APLOGNO(02467)
"cache: Invalidating all cached entities in response to '%s' request for %s",
r->method, r->uri);
cache_invalidate(cache, r);
/* we've got a cache invalidate! tell everyone who cares */
cache_run_cache_status(cache->handle, r, r->headers_out,
AP_CACHE_INVALIDATE, apr_psprintf(r->pool,
"cache invalidated by %s", r->method));
}
}
/* remove ourselves */
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, in);
}
/*
* CACHE filter
* ------------
*
* This filter can be optionally inserted into the filter chain by the admin as
* a marker representing the precise location within the filter chain where
* caching is to be performed.
*
* When the filter chain is set up in the non-quick version of the URL handler,
* the CACHE filter is replaced by the CACHE_OUT or CACHE_SAVE filter,
* effectively inserting the caching filters at the point indicated by the
* admin. The CACHE filter is then removed.
*
* This allows caching to be performed before the content is passed to the
* INCLUDES filter, or to a filter that might perform transformations unique
* to the specific request and that would otherwise be non-cacheable.
*/
static apr_status_t cache_filter(ap_filter_t *f, apr_bucket_brigade *in)
{
cache_server_conf
*conf =
(cache_server_conf *) ap_get_module_config(f->r->server->module_config,
&cache_module);
/* was the quick handler enabled */
if (conf->quick) {
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, f->r, APLOGNO(00776)
"cache: CACHE filter was added in quick handler mode and "
"will be ignored: %s", f->r->unparsed_uri);
}
/* otherwise we may have been bypassed, nothing to see here */
else {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, f->r, APLOGNO(00777)
"cache: CACHE filter was added twice, or was added where "
"the cache has been bypassed and will be ignored: %s",
f->r->unparsed_uri);
}
/* we are just a marker, so let's just remove ourselves */
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, in);
}
/**
* If configured, add the status of the caching attempt to the subprocess
* environment, and if configured, to headers in the response.
*
* The status is saved below the broad category of the status (hit, miss,
* revalidate), as well as a single cache-status key. This can be used for
* conditional logging.
*
* The status is optionally saved to an X-Cache header, and the detail of
* why a particular cache entry was cached (or not cached) is optionally
* saved to an X-Cache-Detail header. This extra detail is useful for
* service developers who may need to know whether their Cache-Control headers
* are working correctly.
*/
static int cache_status(cache_handle_t *h, request_rec *r,
apr_table_t *headers, ap_cache_status_e status, const char *reason)
{
cache_server_conf
*conf =
(cache_server_conf *) ap_get_module_config(r->server->module_config,
&cache_module);
cache_dir_conf *dconf = ap_get_module_config(r->per_dir_config, &cache_module);
int x_cache = 0, x_cache_detail = 0;
switch (status) {
case AP_CACHE_HIT: {
apr_table_setn(r->subprocess_env, AP_CACHE_HIT_ENV, reason);
break;
}
case AP_CACHE_REVALIDATE: {
apr_table_setn(r->subprocess_env, AP_CACHE_REVALIDATE_ENV, reason);
break;
}
case AP_CACHE_MISS: {
apr_table_setn(r->subprocess_env, AP_CACHE_MISS_ENV, reason);
break;
}
case AP_CACHE_INVALIDATE: {
apr_table_setn(r->subprocess_env, AP_CACHE_INVALIDATE_ENV, reason);
break;
}
}
apr_table_setn(r->subprocess_env, AP_CACHE_STATUS_ENV, reason);
if (dconf && dconf->x_cache_set) {
x_cache = dconf->x_cache;
}
else {
x_cache = conf->x_cache;
}
if (x_cache) {
apr_table_setn(headers, "X-Cache", apr_psprintf(r->pool, "%s from %s",
status == AP_CACHE_HIT ? "HIT"
: status == AP_CACHE_REVALIDATE ? "REVALIDATE" : status
== AP_CACHE_INVALIDATE ? "INVALIDATE" : "MISS",
r->server->server_hostname));
}
if (dconf && dconf->x_cache_detail_set) {
x_cache_detail = dconf->x_cache_detail;
}
else {
x_cache_detail = conf->x_cache_detail;
}
if (x_cache_detail) {
apr_table_setn(headers, "X-Cache-Detail", apr_psprintf(r->pool,
"\"%s\" from %s", reason, r->server->server_hostname));
}
return OK;
}
/**
* If an error has occurred, but we have a stale cached entry, restore the
* filter stack from the save filter onwards. The canned error message will
* be discarded in the process, and replaced with the cached response.
*/
static void cache_insert_error_filter(request_rec *r)
{
void *dummy;
cache_dir_conf *dconf;
/* ignore everything except for 5xx errors */
if (r->status < HTTP_INTERNAL_SERVER_ERROR) {
return;
}
dconf = ap_get_module_config(r->per_dir_config, &cache_module);
if (!dconf->stale_on_error) {
return;
}
/* RFC2616 13.8 Errors or Incomplete Response Cache Behavior:
* If a cache receives a 5xx response while attempting to revalidate an
* entry, it MAY either forward this response to the requesting client,
* or act as if the server failed to respond. In the latter case, it MAY
* return a previously received response unless the cached entry
* includes the "must-revalidate" cache-control directive (see section
* 14.9).
*
* This covers the case where the error was generated by our server via
* ap_die().
*/
apr_pool_userdata_get(&dummy, CACHE_CTX_KEY, r->pool);
if (dummy) {
cache_request_rec *cache = (cache_request_rec *) dummy;
ap_remove_output_filter(cache->remove_url_filter);
if (cache->stale_handle && cache->save_filter
&& !cache->stale_handle->cache_obj->info.control.must_revalidate
&& !cache->stale_handle->cache_obj->info.control.proxy_revalidate
&& !cache->stale_handle->cache_obj->info.control.s_maxage) {
const char *warn_head;
cache_server_conf
*conf =
(cache_server_conf *) ap_get_module_config(r->server->module_config,
&cache_module);
/* morph the current save filter into the out filter, and serve from
* cache.
*/
cache->handle = cache->stale_handle;
if (r->main) {
cache->save_filter->frec = cache_out_subreq_filter_handle;
}
else {
cache->save_filter->frec = cache_out_filter_handle;
}
r->output_filters = cache->save_filter;
r->err_headers_out = cache->stale_handle->resp_hdrs;
/* add a revalidation warning */
warn_head = apr_table_get(r->err_headers_out, "Warning");
if ((warn_head == NULL) || ((warn_head != NULL)
&& (ap_strstr_c(warn_head, "111") == NULL))) {
apr_table_mergen(r->err_headers_out, "Warning",
"111 Revalidation failed");
}
cache_run_cache_status(
cache->handle,
r,
r->err_headers_out,
AP_CACHE_HIT,
apr_psprintf(
r->pool,
"cache hit: %d status; stale content returned",
r->status));
/* give someone else the chance to cache the file */
cache_remove_lock(conf, cache, r, NULL);
}
}
return;
}
/* -------------------------------------------------------------- */
/* Setup configurable data */
static void *create_dir_config(apr_pool_t *p, char *dummy)
{
cache_dir_conf *dconf = apr_pcalloc(p, sizeof(cache_dir_conf));
dconf->no_last_mod_ignore = 0;
dconf->store_expired = 0;
dconf->store_private = 0;
dconf->store_nostore = 0;
/* maximum time to cache a document */
dconf->maxex = DEFAULT_CACHE_MAXEXPIRE;
dconf->minex = DEFAULT_CACHE_MINEXPIRE;
/* default time to cache a document */
dconf->defex = DEFAULT_CACHE_EXPIRE;
/* factor used to estimate Expires date from LastModified date */
dconf->factor = DEFAULT_CACHE_LMFACTOR;
dconf->x_cache = DEFAULT_X_CACHE;
dconf->x_cache_detail = DEFAULT_X_CACHE_DETAIL;
dconf->stale_on_error = DEFAULT_CACHE_STALE_ON_ERROR;
/* array of providers for this URL space */
dconf->cacheenable = apr_array_make(p, 10, sizeof(struct cache_enable));
return dconf;
}
static void *merge_dir_config(apr_pool_t *p, void *basev, void *addv) {
cache_dir_conf *new = (cache_dir_conf *) apr_pcalloc(p, sizeof(cache_dir_conf));
cache_dir_conf *add = (cache_dir_conf *) addv;
cache_dir_conf *base = (cache_dir_conf *) basev;
new->no_last_mod_ignore = (add->no_last_mod_ignore_set == 0) ? base->no_last_mod_ignore : add->no_last_mod_ignore;
new->no_last_mod_ignore_set = add->no_last_mod_ignore_set || base->no_last_mod_ignore_set;
new->store_expired = (add->store_expired_set == 0) ? base->store_expired : add->store_expired;
new->store_expired_set = add->store_expired_set || base->store_expired_set;
new->store_private = (add->store_private_set == 0) ? base->store_private : add->store_private;
new->store_private_set = add->store_private_set || base->store_private_set;
new->store_nostore = (add->store_nostore_set == 0) ? base->store_nostore : add->store_nostore;
new->store_nostore_set = add->store_nostore_set || base->store_nostore_set;
/* maximum time to cache a document */
new->maxex = (add->maxex_set == 0) ? base->maxex : add->maxex;
new->maxex_set = add->maxex_set || base->maxex_set;
new->minex = (add->minex_set == 0) ? base->minex : add->minex;
new->minex_set = add->minex_set || base->minex_set;
/* default time to cache a document */
new->defex = (add->defex_set == 0) ? base->defex : add->defex;
new->defex_set = add->defex_set || base->defex_set;
/* factor used to estimate Expires date from LastModified date */
new->factor = (add->factor_set == 0) ? base->factor : add->factor;
new->factor_set = add->factor_set || base->factor_set;
new->x_cache = (add->x_cache_set == 0) ? base->x_cache : add->x_cache;
new->x_cache_set = add->x_cache_set || base->x_cache_set;
new->x_cache_detail = (add->x_cache_detail_set == 0) ? base->x_cache_detail
: add->x_cache_detail;
new->x_cache_detail_set = add->x_cache_detail_set
|| base->x_cache_detail_set;
new->stale_on_error = (add->stale_on_error_set == 0) ? base->stale_on_error
: add->stale_on_error;
new->stale_on_error_set = add->stale_on_error_set
|| base->stale_on_error_set;
new->cacheenable = add->enable_set ? apr_array_append(p, base->cacheenable,
add->cacheenable) : base->cacheenable;
new->enable_set = add->enable_set || base->enable_set;
new->disable = (add->disable_set == 0) ? base->disable : add->disable;
new->disable_set = add->disable_set || base->disable_set;
return new;
}
static void * create_cache_config(apr_pool_t *p, server_rec *s)
{
const char *tmppath = NULL;
cache_server_conf *ps = apr_pcalloc(p, sizeof(cache_server_conf));
/* array of URL prefixes for which caching is enabled */
ps->cacheenable = apr_array_make(p, 10, sizeof(struct cache_enable));
/* array of URL prefixes for which caching is disabled */
ps->cachedisable = apr_array_make(p, 10, sizeof(struct cache_disable));
ps->ignorecachecontrol = 0;
ps->ignorecachecontrol_set = 0;
/* array of headers that should not be stored in cache */
ps->ignore_headers = apr_array_make(p, 10, sizeof(char *));
ps->ignore_headers_set = CACHE_IGNORE_HEADERS_UNSET;
/* flag indicating that query-string should be ignored when caching */
ps->ignorequerystring = 0;
ps->ignorequerystring_set = 0;
/* by default, run in the quick handler */
ps->quick = 1;
ps->quick_set = 0;
/* array of identifiers that should not be used for key calculation */
ps->ignore_session_id = apr_array_make(p, 10, sizeof(char *));
ps->ignore_session_id_set = CACHE_IGNORE_SESSION_ID_UNSET;
ps->lock = 0; /* thundering herd lock defaults to off */
ps->lock_set = 0;
apr_temp_dir_get(&tmppath, p);
if (tmppath) {
ps->lockpath = apr_pstrcat(p, tmppath, DEFAULT_CACHE_LOCKPATH, NULL);
}
ps->lockmaxage = apr_time_from_sec(DEFAULT_CACHE_MAXAGE);
ps->x_cache = DEFAULT_X_CACHE;
ps->x_cache_detail = DEFAULT_X_CACHE_DETAIL;
return ps;
}
static void * merge_cache_config(apr_pool_t *p, void *basev, void *overridesv)
{
cache_server_conf *ps = apr_pcalloc(p, sizeof(cache_server_conf));
cache_server_conf *base = (cache_server_conf *) basev;
cache_server_conf *overrides = (cache_server_conf *) overridesv;
/* array of URL prefixes for which caching is disabled */
ps->cachedisable = apr_array_append(p,
base->cachedisable,
overrides->cachedisable);
/* array of URL prefixes for which caching is enabled */
ps->cacheenable = apr_array_append(p,
base->cacheenable,
overrides->cacheenable);
ps->ignorecachecontrol =
(overrides->ignorecachecontrol_set == 0)
? base->ignorecachecontrol
: overrides->ignorecachecontrol;
ps->ignore_headers =
(overrides->ignore_headers_set == CACHE_IGNORE_HEADERS_UNSET)
? base->ignore_headers
: overrides->ignore_headers;
ps->ignorequerystring =
(overrides->ignorequerystring_set == 0)
? base->ignorequerystring
: overrides->ignorequerystring;
ps->ignore_session_id =
(overrides->ignore_session_id_set == CACHE_IGNORE_SESSION_ID_UNSET)
? base->ignore_session_id
: overrides->ignore_session_id;
ps->lock =
(overrides->lock_set == 0)
? base->lock
: overrides->lock;
ps->lockpath =
(overrides->lockpath_set == 0)
? base->lockpath
: overrides->lockpath;
ps->lockmaxage =
(overrides->lockmaxage_set == 0)
? base->lockmaxage
: overrides->lockmaxage;
ps->quick =
(overrides->quick_set == 0)
? base->quick
: overrides->quick;
ps->x_cache =
(overrides->x_cache_set == 0)
? base->x_cache
: overrides->x_cache;
ps->x_cache_detail =
(overrides->x_cache_detail_set == 0)
? base->x_cache_detail
: overrides->x_cache_detail;
ps->base_uri =
(overrides->base_uri_set == 0)
? base->base_uri
: overrides->base_uri;
return ps;
}
static const char *set_cache_quick_handler(cmd_parms *parms, void *dummy,
int flag)
{
cache_server_conf *conf;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
conf->quick = flag;
conf->quick_set = 1;
return NULL;
}
static const char *set_cache_ignore_no_last_mod(cmd_parms *parms, void *dummy,
int flag)
{
cache_dir_conf *dconf = (cache_dir_conf *)dummy;
dconf->no_last_mod_ignore = flag;
dconf->no_last_mod_ignore_set = 1;
return NULL;
}
static const char *set_cache_ignore_cachecontrol(cmd_parms *parms,
void *dummy, int flag)
{
cache_server_conf *conf;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
conf->ignorecachecontrol = flag;
conf->ignorecachecontrol_set = 1;
return NULL;
}
static const char *set_cache_store_expired(cmd_parms *parms, void *dummy,
int flag)
{
cache_dir_conf *dconf = (cache_dir_conf *)dummy;
dconf->store_expired = flag;
dconf->store_expired_set = 1;
return NULL;
}
static const char *set_cache_store_private(cmd_parms *parms, void *dummy,
int flag)
{
cache_dir_conf *dconf = (cache_dir_conf *)dummy;
dconf->store_private = flag;
dconf->store_private_set = 1;
return NULL;
}
static const char *set_cache_store_nostore(cmd_parms *parms, void *dummy,
int flag)
{
cache_dir_conf *dconf = (cache_dir_conf *)dummy;
dconf->store_nostore = flag;
dconf->store_nostore_set = 1;
return NULL;
}
static const char *add_ignore_header(cmd_parms *parms, void *dummy,
const char *header)
{
cache_server_conf *conf;
char **new;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
if (!strcasecmp(header, "None")) {
/* if header None is listed clear array */
conf->ignore_headers->nelts = 0;
}
else {
if ((conf->ignore_headers_set == CACHE_IGNORE_HEADERS_UNSET) ||
(conf->ignore_headers->nelts)) {
/* Only add header if no "None" has been found in header list
* so far.
* (When 'None' is passed, IGNORE_HEADERS_SET && nelts == 0.)
*/
new = (char **)apr_array_push(conf->ignore_headers);
(*new) = (char *)header;
}
}
conf->ignore_headers_set = CACHE_IGNORE_HEADERS_SET;
return NULL;
}
static const char *add_ignore_session_id(cmd_parms *parms, void *dummy,
const char *identifier)
{
cache_server_conf *conf;
char **new;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
if (!strcasecmp(identifier, "None")) {
/* if identifier None is listed clear array */
conf->ignore_session_id->nelts = 0;
}
else {
if ((conf->ignore_session_id_set == CACHE_IGNORE_SESSION_ID_UNSET) ||
(conf->ignore_session_id->nelts)) {
/*
* Only add identifier if no "None" has been found in identifier
* list so far.
*/
new = (char **)apr_array_push(conf->ignore_session_id);
(*new) = (char *)identifier;
}
}
conf->ignore_session_id_set = CACHE_IGNORE_SESSION_ID_SET;
return NULL;
}
static const char *add_cache_enable(cmd_parms *parms, void *dummy,
const char *type,
const char *url)
{
cache_dir_conf *dconf = (cache_dir_conf *)dummy;
cache_server_conf *conf;
struct cache_enable *new;
const char *err = ap_check_cmd_context(parms,
NOT_IN_DIRECTORY|NOT_IN_LIMIT|NOT_IN_FILES);
if (err != NULL) {
return err;
}
if (*type == '/') {
return apr_psprintf(parms->pool,
"provider (%s) starts with a '/'. Are url and provider switched?",
type);
}
if (!url) {
url = parms->path;
}
if (!url) {
return apr_psprintf(parms->pool,
"CacheEnable provider (%s) is missing an URL.", type);
}
if (parms->path && strncmp(parms->path, url, strlen(parms->path))) {
return "When in a Location, CacheEnable must specify a path or an URL below "
"that location.";
}
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
if (parms->path) {
new = apr_array_push(dconf->cacheenable);
dconf->enable_set = 1;
}
else {
new = apr_array_push(conf->cacheenable);
}
new->type = type;
if (apr_uri_parse(parms->pool, url, &(new->url))) {
return NULL;
}
if (new->url.path) {
new->pathlen = strlen(new->url.path);
} else {
new->pathlen = 1;
new->url.path = "/";
}
return NULL;
}
static const char *add_cache_disable(cmd_parms *parms, void *dummy,
const char *url)
{
cache_dir_conf *dconf = (cache_dir_conf *)dummy;
cache_server_conf *conf;
struct cache_disable *new;
const char *err = ap_check_cmd_context(parms,
NOT_IN_DIRECTORY|NOT_IN_LIMIT|NOT_IN_FILES);
if (err != NULL) {
return err;
}
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
if (parms->path) {
if (!strcasecmp(url, "on")) {
dconf->disable = 1;
dconf->disable_set = 1;
return NULL;
}
else {
return "CacheDisable must be followed by the word 'on' when in a Location.";
}
}
if (!url || (url[0] != '/' && !ap_strchr_c(url, ':'))) {
return "CacheDisable must specify a path or an URL.";
}
new = apr_array_push(conf->cachedisable);
if (apr_uri_parse(parms->pool, url, &(new->url))) {
return NULL;
}
if (new->url.path) {
new->pathlen = strlen(new->url.path);
} else {
new->pathlen = 1;
new->url.path = "/";
}
return NULL;
}
static const char *set_cache_maxex(cmd_parms *parms, void *dummy,
const char *arg)
{
cache_dir_conf *dconf = (cache_dir_conf *)dummy;
dconf->maxex = (apr_time_t) (atol(arg) * MSEC_ONE_SEC);
dconf->maxex_set = 1;
return NULL;
}
static const char *set_cache_minex(cmd_parms *parms, void *dummy,
const char *arg)
{
cache_dir_conf *dconf = (cache_dir_conf *)dummy;
dconf->minex = (apr_time_t) (atol(arg) * MSEC_ONE_SEC);
dconf->minex_set = 1;
return NULL;
}
static const char *set_cache_defex(cmd_parms *parms, void *dummy,
const char *arg)
{
cache_dir_conf *dconf = (cache_dir_conf *)dummy;
dconf->defex = (apr_time_t) (atol(arg) * MSEC_ONE_SEC);
dconf->defex_set = 1;
return NULL;
}
static const char *set_cache_factor(cmd_parms *parms, void *dummy,
const char *arg)
{
cache_dir_conf *dconf = (cache_dir_conf *)dummy;
double val;
if (sscanf(arg, "%lg", &val) != 1) {
return "CacheLastModifiedFactor value must be a float";
}
dconf->factor = val;
dconf->factor_set = 1;
return NULL;
}
static const char *set_cache_ignore_querystring(cmd_parms *parms, void *dummy,
int flag)
{
cache_server_conf *conf;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
conf->ignorequerystring = flag;
conf->ignorequerystring_set = 1;
return NULL;
}
static const char *set_cache_lock(cmd_parms *parms, void *dummy,
int flag)
{
cache_server_conf *conf;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
conf->lock = flag;
conf->lock_set = 1;
return NULL;
}
static const char *set_cache_lock_path(cmd_parms *parms, void *dummy,
const char *arg)
{
cache_server_conf *conf;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
conf->lockpath = ap_server_root_relative(parms->pool, arg);
if (!conf->lockpath) {
return apr_pstrcat(parms->pool, "Invalid CacheLockPath path ",
arg, NULL);
}
conf->lockpath_set = 1;
return NULL;
}
static const char *set_cache_lock_maxage(cmd_parms *parms, void *dummy,
const char *arg)
{
cache_server_conf *conf;
apr_int64_t seconds;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
seconds = apr_atoi64(arg);
if (seconds <= 0) {
return "CacheLockMaxAge value must be a non-zero positive integer";
}
conf->lockmaxage = apr_time_from_sec(seconds);
conf->lockmaxage_set = 1;
return NULL;
}
static const char *set_cache_x_cache(cmd_parms *parms, void *dummy, int flag)
{
if (parms->path) {
cache_dir_conf *dconf = (cache_dir_conf *)dummy;
dconf->x_cache = flag;
dconf->x_cache_set = 1;
}
else {
cache_server_conf *conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
conf->x_cache = flag;
conf->x_cache_set = 1;
}
return NULL;
}
static const char *set_cache_x_cache_detail(cmd_parms *parms, void *dummy, int flag)
{
if (parms->path) {
cache_dir_conf *dconf = (cache_dir_conf *)dummy;
dconf->x_cache_detail = flag;
dconf->x_cache_detail_set = 1;
}
else {
cache_server_conf *conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
conf->x_cache_detail = flag;
conf->x_cache_detail_set = 1;
}
return NULL;
}
static const char *set_cache_key_base_url(cmd_parms *parms, void *dummy,
const char *arg)
{
cache_server_conf *conf;
apr_status_t rv;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
conf->base_uri = apr_pcalloc(parms->pool, sizeof(apr_uri_t));
rv = apr_uri_parse(parms->pool, arg, conf->base_uri);
if (rv != APR_SUCCESS) {
return apr_psprintf(parms->pool, "Could not parse '%s' as an URL.", arg);
}
else if (!conf->base_uri->scheme && !conf->base_uri->hostname &&
!conf->base_uri->port_str) {
return apr_psprintf(parms->pool, "URL '%s' must contain at least one of a scheme, a hostname or a port.", arg);
}
conf->base_uri_set = 1;
return NULL;
}
static const char *set_cache_stale_on_error(cmd_parms *parms, void *dummy,
int flag)
{
cache_dir_conf *dconf = (cache_dir_conf *)dummy;
dconf->stale_on_error = flag;
dconf->stale_on_error_set = 1;
return NULL;
}
static int cache_post_config(apr_pool_t *p, apr_pool_t *plog,
apr_pool_t *ptemp, server_rec *s)
{
/* This is the means by which unusual (non-unix) os's may find alternate
* means to run a given command (e.g. shebang/registry parsing on Win32)
*/
cache_generate_key = APR_RETRIEVE_OPTIONAL_FN(ap_cache_generate_key);
if (!cache_generate_key) {
cache_generate_key = cache_generate_key_default;
}
return OK;
}
static const command_rec cache_cmds[] =
{
/* XXX
* Consider a new config directive that enables loading specific cache
* implementations (like mod_cache_mem, mod_cache_file, etc.).
* Rather than using a LoadModule directive, admin would use something
* like CacheModule mem_cache_module | file_cache_module, etc,
* which would cause the approprpriate cache module to be loaded.
* This is more intuitive that requiring a LoadModule directive.
*/
AP_INIT_TAKE12("CacheEnable", add_cache_enable, NULL, RSRC_CONF|ACCESS_CONF,
"A cache type and partial URL prefix below which "
"caching is enabled"),
AP_INIT_TAKE1("CacheDisable", add_cache_disable, NULL, RSRC_CONF|ACCESS_CONF,
"A partial URL prefix below which caching is disabled"),
AP_INIT_TAKE1("CacheMaxExpire", set_cache_maxex, NULL, RSRC_CONF|ACCESS_CONF,
"The maximum time in seconds to cache a document"),
AP_INIT_TAKE1("CacheMinExpire", set_cache_minex, NULL, RSRC_CONF|ACCESS_CONF,
"The minimum time in seconds to cache a document"),
AP_INIT_TAKE1("CacheDefaultExpire", set_cache_defex, NULL, RSRC_CONF|ACCESS_CONF,
"The default time in seconds to cache a document"),
AP_INIT_FLAG("CacheQuickHandler", set_cache_quick_handler, NULL,
RSRC_CONF,
"Run the cache in the quick handler, default on"),
AP_INIT_FLAG("CacheIgnoreNoLastMod", set_cache_ignore_no_last_mod, NULL,
RSRC_CONF|ACCESS_CONF,
"Ignore Responses where there is no Last Modified Header"),
AP_INIT_FLAG("CacheIgnoreCacheControl", set_cache_ignore_cachecontrol,
NULL, RSRC_CONF,
"Ignore requests from the client for uncached content"),
AP_INIT_FLAG("CacheStoreExpired", set_cache_store_expired,
NULL, RSRC_CONF|ACCESS_CONF,
"Ignore expiration dates when populating cache, resulting in "
"an If-Modified-Since request to the backend on retrieval"),
AP_INIT_FLAG("CacheStorePrivate", set_cache_store_private,
NULL, RSRC_CONF|ACCESS_CONF,
"Ignore 'Cache-Control: private' and store private content"),
AP_INIT_FLAG("CacheStoreNoStore", set_cache_store_nostore,
NULL, RSRC_CONF|ACCESS_CONF,
"Ignore 'Cache-Control: no-store' and store sensitive content"),
AP_INIT_ITERATE("CacheIgnoreHeaders", add_ignore_header, NULL, RSRC_CONF,
"A space separated list of headers that should not be "
"stored by the cache"),
AP_INIT_FLAG("CacheIgnoreQueryString", set_cache_ignore_querystring,
NULL, RSRC_CONF,
"Ignore query-string when caching"),
AP_INIT_ITERATE("CacheIgnoreURLSessionIdentifiers", add_ignore_session_id,
NULL, RSRC_CONF, "A space separated list of session "
"identifiers that should be ignored for creating the key "
"of the cached entity."),
AP_INIT_TAKE1("CacheLastModifiedFactor", set_cache_factor, NULL, RSRC_CONF|ACCESS_CONF,
"The factor used to estimate Expires date from "
"LastModified date"),
AP_INIT_FLAG("CacheLock", set_cache_lock,
NULL, RSRC_CONF,
"Enable or disable the thundering herd lock."),
AP_INIT_TAKE1("CacheLockPath", set_cache_lock_path, NULL, RSRC_CONF,
"The thundering herd lock path. Defaults to the '"
DEFAULT_CACHE_LOCKPATH "' directory in the system "
"temp directory."),
AP_INIT_TAKE1("CacheLockMaxAge", set_cache_lock_maxage, NULL, RSRC_CONF,
"Maximum age of any thundering herd lock."),
AP_INIT_FLAG("CacheHeader", set_cache_x_cache, NULL, RSRC_CONF | ACCESS_CONF,
"Add a X-Cache header to responses. Default is off."),
AP_INIT_FLAG("CacheDetailHeader", set_cache_x_cache_detail, NULL,
RSRC_CONF | ACCESS_CONF,
"Add a X-Cache-Detail header to responses. Default is off."),
AP_INIT_TAKE1("CacheKeyBaseURL", set_cache_key_base_url, NULL, RSRC_CONF,
"Override the base URL of reverse proxied cache keys."),
AP_INIT_FLAG("CacheStaleOnError", set_cache_stale_on_error,
NULL, RSRC_CONF|ACCESS_CONF,
"Serve stale content on 5xx errors if present. Defaults to on."),
{NULL}
};
static void register_hooks(apr_pool_t *p)
{
/* cache initializer */
/* cache quick handler */
ap_hook_quick_handler(cache_quick_handler, NULL, NULL, APR_HOOK_FIRST);
/* cache handler */
ap_hook_handler(cache_handler, NULL, NULL, APR_HOOK_REALLY_FIRST);
/* cache status */
cache_hook_cache_status(cache_status, NULL, NULL, APR_HOOK_MIDDLE);
/* cache error handler */
ap_hook_insert_error_filter(cache_insert_error_filter, NULL, NULL, APR_HOOK_MIDDLE);
/* cache filters
* XXX The cache filters need to run right after the handlers and before
* any other filters. Consider creating AP_FTYPE_CACHE for this purpose.
*
* Depending on the type of request (subrequest / main request) they
* need to be run before AP_FTYPE_CONTENT_SET / after AP_FTYPE_CONTENT_SET
* filters. Thus create two filter handles for each type:
* cache_save_filter_handle / cache_out_filter_handle to be used by
* main requests and
* cache_save_subreq_filter_handle / cache_out_subreq_filter_handle
* to be run by subrequest
*/
/*
* CACHE is placed into the filter chain at an admin specified location,
* and when the cache_handler is run, the CACHE filter is swapped with
* the CACHE_OUT filter, or CACHE_SAVE filter as appropriate. This has
* the effect of offering optional fine control of where the cache is
* inserted into the filter chain.
*/
cache_filter_handle =
ap_register_output_filter("CACHE",
cache_filter,
NULL,
AP_FTYPE_RESOURCE);
/*
* CACHE_SAVE must go into the filter chain after a possible DEFLATE
* filter to ensure that the compressed content is stored.
* Incrementing filter type by 1 ensures this happens.
*/
cache_save_filter_handle =
ap_register_output_filter("CACHE_SAVE",
cache_save_filter,
NULL,
AP_FTYPE_CONTENT_SET+1);
/*
* CACHE_SAVE_SUBREQ must go into the filter chain before SUBREQ_CORE to
* handle subrequsts. Decrementing filter type by 1 ensures this
* happens.
*/
cache_save_subreq_filter_handle =
ap_register_output_filter("CACHE_SAVE_SUBREQ",
cache_save_filter,
NULL,
AP_FTYPE_CONTENT_SET-1);
/*
* CACHE_OUT must go into the filter chain after a possible DEFLATE
* filter to ensure that already compressed cache objects do not
* get compressed again. Incrementing filter type by 1 ensures
* this happens.
*/
cache_out_filter_handle =
ap_register_output_filter("CACHE_OUT",
cache_out_filter,
NULL,
AP_FTYPE_CONTENT_SET+1);
/*
* CACHE_OUT_SUBREQ must go into the filter chain before SUBREQ_CORE to
* handle subrequsts. Decrementing filter type by 1 ensures this
* happens.
*/
cache_out_subreq_filter_handle =
ap_register_output_filter("CACHE_OUT_SUBREQ",
cache_out_filter,
NULL,
AP_FTYPE_CONTENT_SET-1);
/* CACHE_REMOVE_URL has to be a protocol filter to ensure that is
* run even if the response is a canned error message, which
* removes the content filters.
*/
cache_remove_url_filter_handle =
ap_register_output_filter("CACHE_REMOVE_URL",
cache_remove_url_filter,
NULL,
AP_FTYPE_PROTOCOL);
cache_invalidate_filter_handle =
ap_register_output_filter("CACHE_INVALIDATE",
cache_invalidate_filter,
NULL,
AP_FTYPE_PROTOCOL);
ap_hook_post_config(cache_post_config, NULL, NULL, APR_HOOK_REALLY_FIRST);
}
AP_DECLARE_MODULE(cache) =
{
STANDARD20_MODULE_STUFF,
create_dir_config, /* create per-directory config structure */
merge_dir_config, /* merge per-directory config structures */
create_cache_config, /* create per-server config structure */
merge_cache_config, /* merge per-server config structures */
cache_cmds, /* command apr_table_t */
register_hooks
};
APR_HOOK_STRUCT(
APR_HOOK_LINK(cache_status)
)
APR_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL(cache, CACHE, int, cache_status,
(cache_handle_t *h, request_rec *r,
apr_table_t *headers, ap_cache_status_e status,
const char *reason), (h, r, headers, status, reason),
OK, DECLINED)