/* 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 *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, **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 (overwriten 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; } 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; /* 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) { char *errp; if (apr_strtoff(&size, cl, &errp, 10) || *errp || size < 0) { cl = NULL; /* parse error, see next 'if' block */ } } 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 > 299) { ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02466) "cache: response status to '%s' method is %d (>299), 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 * implememtations (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)