| /* 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_util.h" |
| #include <ap_provider.h> |
| |
| APLOG_USE_MODULE(cache); |
| |
| /* -------------------------------------------------------------- */ |
| |
| extern APR_OPTIONAL_FN_TYPE(ap_cache_generate_key) *cache_generate_key; |
| |
| extern module AP_MODULE_DECLARE_DATA cache_module; |
| |
| /* Determine if "url" matches the hostname, scheme and port and path |
| * in "filter". All but the path comparisons are case-insensitive. |
| */ |
| static int uri_meets_conditions(const apr_uri_t *filter, const int pathlen, |
| const apr_uri_t *url) |
| { |
| |
| /* Scheme, hostname port and local part. The filter URI and the |
| * URI we test may have the following shapes: |
| * /<path> |
| * <scheme>[:://<hostname>[:<port>][/<path>]] |
| * That is, if there is no scheme then there must be only the path, |
| * and we check only the path; if there is a scheme, we check the |
| * scheme for equality, and then if present we match the hostname, |
| * and then if present match the port, and finally the path if any. |
| * |
| * Note that this means that "/<path>" only matches local paths, |
| * and to match proxied paths one *must* specify the scheme. |
| */ |
| |
| /* Is the filter is just for a local path or a proxy URI? */ |
| if (!filter->scheme) { |
| if (url->scheme || url->hostname) { |
| return 0; |
| } |
| } |
| else { |
| /* The URI scheme must be present and identical except for case. */ |
| if (!url->scheme || ap_cstr_casecmp(filter->scheme, url->scheme)) { |
| return 0; |
| } |
| |
| /* If the filter hostname is null or empty it matches any hostname, |
| * if it begins with a "*" it matches the _end_ of the URI hostname |
| * excluding the "*", if it begins with a "." it matches the _end_ |
| * of the URI * hostname including the ".", otherwise it must match |
| * the URI hostname exactly. */ |
| |
| if (filter->hostname && filter->hostname[0]) { |
| if (filter->hostname[0] == '.') { |
| const size_t fhostlen = strlen(filter->hostname); |
| const size_t uhostlen = url->hostname ? strlen(url->hostname) : 0; |
| |
| if (fhostlen > uhostlen |
| || (url->hostname |
| && strcasecmp(filter->hostname, |
| url->hostname + uhostlen - fhostlen))) { |
| return 0; |
| } |
| } |
| else if (filter->hostname[0] == '*') { |
| const size_t fhostlen = strlen(filter->hostname + 1); |
| const size_t uhostlen = url->hostname ? strlen(url->hostname) : 0; |
| |
| if (fhostlen > uhostlen |
| || (url->hostname |
| && strcasecmp(filter->hostname + 1, |
| url->hostname + uhostlen - fhostlen))) { |
| return 0; |
| } |
| } |
| else if (!url->hostname || strcasecmp(filter->hostname, url->hostname)) { |
| return 0; |
| } |
| } |
| |
| /* If the filter port is empty it matches any URL port. |
| * If the filter or URL port are missing, or the URL port is |
| * empty, they default to the port for their scheme. */ |
| |
| if (!(filter->port_str && !filter->port_str[0])) { |
| /* NOTE: ap_port_of_scheme will return 0 if given NULL input */ |
| const unsigned fport = filter->port_str ? filter->port |
| : apr_uri_port_of_scheme(filter->scheme); |
| const unsigned uport = (url->port_str && url->port_str[0]) |
| ? url->port : apr_uri_port_of_scheme(url->scheme); |
| |
| if (fport != uport) { |
| return 0; |
| } |
| } |
| } |
| |
| /* For HTTP caching purposes, an empty (NULL) path is equivalent to |
| * a single "/" path. RFCs 3986/2396 |
| */ |
| if (!url->path) { |
| if (*filter->path == '/' && pathlen == 1) { |
| return 1; |
| } |
| else { |
| return 0; |
| } |
| } |
| |
| /* Url has met all of the filter conditions so far, determine |
| * if the paths match. |
| */ |
| return !strncmp(filter->path, url->path, pathlen); |
| } |
| |
| static cache_provider_list *get_provider(request_rec *r, struct cache_enable *ent, |
| cache_provider_list *providers) |
| { |
| /* Fetch from global config and add to the list. */ |
| cache_provider *provider; |
| provider = ap_lookup_provider(CACHE_PROVIDER_GROUP, ent->type, |
| "0"); |
| if (!provider) { |
| /* Log an error! */ |
| } |
| else { |
| cache_provider_list *newp; |
| newp = apr_pcalloc(r->pool, sizeof(cache_provider_list)); |
| newp->provider_name = ent->type; |
| newp->provider = provider; |
| |
| if (!providers) { |
| providers = newp; |
| } |
| else { |
| cache_provider_list *last = providers; |
| |
| while (last->next) { |
| if (last->provider == provider) { |
| return providers; |
| } |
| last = last->next; |
| } |
| if (last->provider == provider) { |
| return providers; |
| } |
| last->next = newp; |
| } |
| } |
| |
| return providers; |
| } |
| |
| cache_provider_list *cache_get_providers(request_rec *r, |
| cache_server_conf *conf, |
| apr_uri_t uri) |
| { |
| cache_dir_conf *dconf = ap_get_module_config(r->per_dir_config, &cache_module); |
| cache_provider_list *providers = NULL; |
| int i; |
| |
| /* per directory cache disable */ |
| if (dconf->disable) { |
| return NULL; |
| } |
| |
| /* global cache disable */ |
| for (i = 0; i < conf->cachedisable->nelts; i++) { |
| struct cache_disable *ent = |
| (struct cache_disable *)conf->cachedisable->elts; |
| if (uri_meets_conditions(&ent[i].url, ent[i].pathlen, &uri)) { |
| /* Stop searching now. */ |
| return NULL; |
| } |
| } |
| |
| /* loop through all the per directory cacheenable entries */ |
| for (i = 0; i < dconf->cacheenable->nelts; i++) { |
| struct cache_enable *ent = |
| (struct cache_enable *)dconf->cacheenable->elts; |
| providers = get_provider(r, &ent[i], providers); |
| } |
| |
| /* loop through all the global cacheenable entries */ |
| for (i = 0; i < conf->cacheenable->nelts; i++) { |
| struct cache_enable *ent = |
| (struct cache_enable *)conf->cacheenable->elts; |
| if (uri_meets_conditions(&ent[i].url, ent[i].pathlen, &uri)) { |
| providers = get_provider(r, &ent[i], providers); |
| } |
| } |
| |
| return providers; |
| } |
| |
| |
| /* do a HTTP/1.1 age calculation */ |
| CACHE_DECLARE(apr_int64_t) ap_cache_current_age(cache_info *info, |
| const apr_time_t age_value, |
| apr_time_t now) |
| { |
| apr_time_t apparent_age, corrected_received_age, response_delay, |
| corrected_initial_age, resident_time, current_age, |
| age_value_usec; |
| |
| age_value_usec = apr_time_from_sec(age_value); |
| |
| /* Perform an HTTP/1.1 age calculation. (RFC2616 13.2.3) */ |
| |
| apparent_age = MAX(0, info->response_time - info->date); |
| corrected_received_age = MAX(apparent_age, age_value_usec); |
| response_delay = info->response_time - info->request_time; |
| corrected_initial_age = corrected_received_age + response_delay; |
| resident_time = now - info->response_time; |
| current_age = corrected_initial_age + resident_time; |
| |
| if (current_age < 0) { |
| current_age = 0; |
| } |
| |
| return apr_time_sec(current_age); |
| } |
| |
| /** |
| * Try obtain a cache wide lock on the given cache key. |
| * |
| * If we return APR_SUCCESS, we obtained the lock, and we are clear to |
| * proceed to the backend. If we return APR_EEXIST, then the lock is |
| * already locked, someone else has gone to refresh the backend data |
| * already, so we must return stale data with a warning in the mean |
| * time. If we return anything else, then something has gone pear |
| * shaped, and we allow the request through to the backend regardless. |
| * |
| * This lock is created from the request pool, meaning that should |
| * something go wrong and the lock isn't deleted on return of the |
| * request headers from the backend for whatever reason, at worst the |
| * lock will be cleaned up when the request dies or finishes. |
| * |
| * If something goes truly bananas and the lock isn't deleted when the |
| * request dies, the lock will be trashed when its max-age is reached, |
| * or when a request arrives containing a Cache-Control: no-cache. At |
| * no point is it possible for this lock to permanently deny access to |
| * the backend. |
| */ |
| apr_status_t cache_try_lock(cache_server_conf *conf, cache_request_rec *cache, |
| request_rec *r) |
| { |
| apr_status_t status; |
| const char *lockname; |
| const char *path; |
| char dir[5]; |
| apr_time_t now = apr_time_now(); |
| apr_finfo_t finfo; |
| apr_file_t *lockfile; |
| void *dummy; |
| |
| finfo.mtime = 0; |
| |
| if (!conf || !conf->lock || !conf->lockpath) { |
| /* no locks configured, leave */ |
| return APR_SUCCESS; |
| } |
| |
| /* lock already obtained earlier? if so, success */ |
| apr_pool_userdata_get(&dummy, CACHE_LOCKFILE_KEY, r->pool); |
| if (dummy) { |
| return APR_SUCCESS; |
| } |
| |
| /* create the key if it doesn't exist */ |
| if (!cache->key) { |
| cache_handle_t *h; |
| /* |
| * Try to use the key of a possible open but stale cache |
| * entry if we have one. |
| */ |
| if (cache->handle != NULL) { |
| h = cache->handle; |
| } |
| else { |
| h = cache->stale_handle; |
| } |
| if ((h != NULL) && |
| (h->cache_obj != NULL) && |
| (h->cache_obj->key != NULL)) { |
| cache->key = apr_pstrdup(r->pool, h->cache_obj->key); |
| } |
| else { |
| cache_generate_key(r, r->pool, &cache->key); |
| } |
| } |
| |
| /* create a hashed filename from the key, and save it for later */ |
| lockname = ap_cache_generate_name(r->pool, 0, 0, cache->key); |
| |
| /* lock files represent discrete just-went-stale URLs "in flight", so |
| * we support a simple two level directory structure, more is overkill. |
| */ |
| dir[0] = '/'; |
| dir[1] = lockname[0]; |
| dir[2] = '/'; |
| dir[3] = lockname[1]; |
| dir[4] = 0; |
| |
| /* make the directories */ |
| path = apr_pstrcat(r->pool, conf->lockpath, dir, NULL); |
| if (APR_SUCCESS != (status = apr_dir_make_recursive(path, |
| APR_UREAD|APR_UWRITE|APR_UEXECUTE, r->pool))) { |
| ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(00778) |
| "Could not create a cache lock directory: %s", |
| path); |
| return status; |
| } |
| lockname = apr_pstrcat(r->pool, path, "/", lockname, NULL); |
| apr_pool_userdata_set(lockname, CACHE_LOCKNAME_KEY, NULL, r->pool); |
| |
| /* is an existing lock file too old? */ |
| status = apr_stat(&finfo, lockname, |
| APR_FINFO_MTIME | APR_FINFO_NLINK, r->pool); |
| if (!(APR_STATUS_IS_ENOENT(status)) && APR_SUCCESS != status) { |
| ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(00779) |
| "Could not stat a cache lock file: %s", |
| lockname); |
| return status; |
| } |
| if ((status == APR_SUCCESS) && (((now - finfo.mtime) > conf->lockmaxage) |
| || (now < finfo.mtime))) { |
| ap_log_rerror(APLOG_MARK, APLOG_INFO, status, r, APLOGNO(00780) |
| "Cache lock file for '%s' too old, removing: %s", |
| r->uri, lockname); |
| apr_file_remove(lockname, r->pool); |
| } |
| |
| /* try obtain a lock on the file */ |
| if (APR_SUCCESS == (status = apr_file_open(&lockfile, lockname, |
| APR_WRITE | APR_CREATE | APR_EXCL | APR_DELONCLOSE, |
| APR_UREAD | APR_UWRITE, r->pool))) { |
| apr_pool_userdata_set(lockfile, CACHE_LOCKFILE_KEY, NULL, r->pool); |
| } |
| return status; |
| |
| } |
| |
| /** |
| * Remove the cache lock, if present. |
| * |
| * First, try to close the file handle, whose delete-on-close should |
| * kill the file. Otherwise, just delete the file by name. |
| * |
| * If no lock name has yet been calculated, do the calculation of the |
| * lock name first before trying to delete the file. |
| * |
| * If an optional bucket brigade is passed, the lock will only be |
| * removed if the bucket brigade contains an EOS bucket. |
| */ |
| apr_status_t cache_remove_lock(cache_server_conf *conf, |
| cache_request_rec *cache, request_rec *r, apr_bucket_brigade *bb) |
| { |
| void *dummy; |
| const char *lockname; |
| |
| if (!conf || !conf->lock || !conf->lockpath) { |
| /* no locks configured, leave */ |
| return APR_SUCCESS; |
| } |
| if (bb) { |
| apr_bucket *e; |
| int eos_found = 0; |
| for (e = APR_BRIGADE_FIRST(bb); |
| e != APR_BRIGADE_SENTINEL(bb); |
| e = APR_BUCKET_NEXT(e)) |
| { |
| if (APR_BUCKET_IS_EOS(e)) { |
| eos_found = 1; |
| break; |
| } |
| } |
| if (!eos_found) { |
| /* no eos found in brigade, don't delete anything just yet, |
| * we are not done. |
| */ |
| return APR_SUCCESS; |
| } |
| } |
| apr_pool_userdata_get(&dummy, CACHE_LOCKFILE_KEY, r->pool); |
| if (dummy) { |
| return apr_file_close((apr_file_t *)dummy); |
| } |
| apr_pool_userdata_get(&dummy, CACHE_LOCKNAME_KEY, r->pool); |
| lockname = (const char *)dummy; |
| if (!lockname) { |
| char dir[5]; |
| |
| /* create the key if it doesn't exist */ |
| if (!cache->key) { |
| cache_generate_key(r, r->pool, &cache->key); |
| } |
| |
| /* create a hashed filename from the key, and save it for later */ |
| lockname = ap_cache_generate_name(r->pool, 0, 0, cache->key); |
| |
| /* lock files represent discrete just-went-stale URLs "in flight", so |
| * we support a simple two level directory structure, more is overkill. |
| */ |
| dir[0] = '/'; |
| dir[1] = lockname[0]; |
| dir[2] = '/'; |
| dir[3] = lockname[1]; |
| dir[4] = 0; |
| |
| lockname = apr_pstrcat(r->pool, conf->lockpath, dir, "/", lockname, NULL); |
| } |
| return apr_file_remove(lockname, r->pool); |
| } |
| |
| int ap_cache_check_no_cache(cache_request_rec *cache, request_rec *r) |
| { |
| |
| cache_server_conf *conf = |
| (cache_server_conf *)ap_get_module_config(r->server->module_config, |
| &cache_module); |
| |
| /* |
| * At this point, we may have data cached, but the request may have |
| * specified that cached data may not be used in a response. |
| * |
| * This is covered under RFC2616 section 14.9.4 (Cache Revalidation and |
| * Reload Controls). |
| * |
| * - RFC2616 14.9.4 End to end reload, Cache-Control: no-cache, or Pragma: |
| * no-cache. The server MUST NOT use a cached copy when responding to such |
| * a request. |
| */ |
| |
| /* This value comes from the client's initial request. */ |
| if (!cache->control_in.parsed) { |
| const char *cc_req = cache_table_getm(r->pool, r->headers_in, |
| "Cache-Control"); |
| const char *pragma = cache_table_getm(r->pool, r->headers_in, "Pragma"); |
| ap_cache_control(r, &cache->control_in, cc_req, pragma, r->headers_in); |
| } |
| |
| if (cache->control_in.no_cache) { |
| |
| if (!conf->ignorecachecontrol) { |
| return 0; |
| } |
| else { |
| ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(02657) |
| "Incoming request is asking for an uncached version of " |
| "%s, but we have been configured to ignore it and serve " |
| "cached content anyway", r->unparsed_uri); |
| } |
| } |
| |
| return 1; |
| } |
| |
| int ap_cache_check_no_store(cache_request_rec *cache, request_rec *r) |
| { |
| |
| cache_server_conf *conf = |
| (cache_server_conf *)ap_get_module_config(r->server->module_config, |
| &cache_module); |
| |
| /* |
| * At this point, we may have data cached, but the request may have |
| * specified that cached data may not be used in a response. |
| * |
| * - RFC2616 14.9.2 What May be Stored by Caches. If Cache-Control: |
| * no-store arrives, do not serve from or store to the cache. |
| */ |
| |
| /* This value comes from the client's initial request. */ |
| if (!cache->control_in.parsed) { |
| const char *cc_req = cache_table_getm(r->pool, r->headers_in, |
| "Cache-Control"); |
| const char *pragma = cache_table_getm(r->pool, r->headers_in, "Pragma"); |
| ap_cache_control(r, &cache->control_in, cc_req, pragma, r->headers_in); |
| } |
| |
| if (cache->control_in.no_store) { |
| |
| if (!conf->ignorecachecontrol) { |
| /* We're not allowed to serve a cached copy */ |
| return 0; |
| } |
| else { |
| ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(02658) |
| "Incoming request is asking for a no-store version of " |
| "%s, but we have been configured to ignore it and serve " |
| "cached content anyway", r->unparsed_uri); |
| } |
| } |
| |
| return 1; |
| } |
| |
| int cache_check_freshness(cache_handle_t *h, cache_request_rec *cache, |
| request_rec *r) |
| { |
| apr_status_t status; |
| apr_int64_t age, maxage_req, maxage_cresp, maxage, smaxage, maxstale; |
| apr_int64_t minfresh; |
| const char *cc_req; |
| const char *pragma; |
| const char *agestr = NULL; |
| apr_time_t age_c = 0; |
| cache_info *info = &(h->cache_obj->info); |
| const char *warn_head; |
| cache_server_conf *conf = |
| (cache_server_conf *)ap_get_module_config(r->server->module_config, |
| &cache_module); |
| |
| /* |
| * We now want to check if our cached data is still fresh. This depends |
| * on a few things, in this order: |
| * |
| * - RFC2616 14.9.4 End to end reload, Cache-Control: no-cache. no-cache |
| * in either the request or the cached response means that we must |
| * perform the request unconditionally, and ignore cached content. We |
| * should never reach here, but if we do, mark the content as stale, |
| * as this is the best we can do. |
| * |
| * - RFC2616 14.32 Pragma: no-cache This is treated the same as |
| * Cache-Control: no-cache. |
| * |
| * - RFC2616 14.9.3 Cache-Control: max-stale, must-revalidate, |
| * proxy-revalidate if the max-stale request header exists, modify the |
| * stale calculations below so that an object can be at most <max-stale> |
| * seconds stale before we request a revalidation, _UNLESS_ a |
| * must-revalidate or proxy-revalidate cached response header exists to |
| * stop us doing this. |
| * |
| * - RFC2616 14.9.3 Cache-Control: s-maxage the origin server specifies the |
| * maximum age an object can be before it is considered stale. This |
| * directive has the effect of proxy|must revalidate, which in turn means |
| * simple ignore any max-stale setting. |
| * |
| * - RFC2616 14.9.4 Cache-Control: max-age this header can appear in both |
| * requests and responses. If both are specified, the smaller of the two |
| * takes priority. |
| * |
| * - RFC2616 14.21 Expires: if this request header exists in the cached |
| * entity, and it's value is in the past, it has expired. |
| * |
| */ |
| |
| /* This value comes from the client's initial request. */ |
| cc_req = apr_table_get(r->headers_in, "Cache-Control"); |
| pragma = apr_table_get(r->headers_in, "Pragma"); |
| |
| ap_cache_control(r, &cache->control_in, cc_req, pragma, r->headers_in); |
| |
| if (cache->control_in.no_cache) { |
| |
| if (!conf->ignorecachecontrol) { |
| /* Treat as stale, causing revalidation */ |
| return 0; |
| } |
| |
| ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(00781) |
| "Incoming request is asking for a uncached version of " |
| "%s, but we have been configured to ignore it and " |
| "serve a cached response anyway", |
| r->unparsed_uri); |
| } |
| |
| /* These come from the cached entity. */ |
| if (h->cache_obj->info.control.no_cache |
| || h->cache_obj->info.control.invalidated) { |
| /* |
| * The cached entity contained Cache-Control: no-cache, or a |
| * no-cache with a header present, or a private with a header |
| * present, or the cached entity has been invalidated in the |
| * past, so treat as stale causing revalidation. |
| */ |
| return 0; |
| } |
| |
| if ((agestr = apr_table_get(h->resp_hdrs, "Age"))) { |
| char *endp; |
| apr_off_t offt; |
| if (!apr_strtoff(&offt, agestr, &endp, 10) |
| && endp > agestr && !*endp) { |
| age_c = offt; |
| } |
| } |
| |
| /* calculate age of object */ |
| age = ap_cache_current_age(info, age_c, r->request_time); |
| |
| /* extract s-maxage */ |
| smaxage = h->cache_obj->info.control.s_maxage_value; |
| |
| /* extract max-age from request */ |
| maxage_req = -1; |
| if (!conf->ignorecachecontrol) { |
| maxage_req = cache->control_in.max_age_value; |
| } |
| |
| /* |
| * extract max-age from response, if both s-maxage and max-age, s-maxage |
| * takes priority |
| */ |
| if (smaxage != -1) { |
| maxage_cresp = smaxage; |
| } |
| else { |
| maxage_cresp = h->cache_obj->info.control.max_age_value; |
| } |
| |
| /* |
| * if both maxage request and response, the smaller one takes priority |
| */ |
| if (maxage_req == -1) { |
| maxage = maxage_cresp; |
| } |
| else if (maxage_cresp == -1) { |
| maxage = maxage_req; |
| } |
| else { |
| maxage = MIN(maxage_req, maxage_cresp); |
| } |
| |
| /* extract max-stale */ |
| if (cache->control_in.max_stale) { |
| if(cache->control_in.max_stale_value != -1) { |
| maxstale = cache->control_in.max_stale_value; |
| } |
| else { |
| /* |
| * If no value is assigned to max-stale, then the client is willing |
| * to accept a stale response of any age (RFC2616 14.9.3). We will |
| * set it to one year in this case as this situation is somewhat |
| * similar to a "never expires" Expires header (RFC2616 14.21) |
| * which is set to a date one year from the time the response is |
| * sent in this case. |
| */ |
| maxstale = APR_INT64_C(86400*365); |
| } |
| } |
| else { |
| maxstale = 0; |
| } |
| |
| /* extract min-fresh */ |
| if (!conf->ignorecachecontrol && cache->control_in.min_fresh) { |
| minfresh = cache->control_in.min_fresh_value; |
| } |
| else { |
| minfresh = 0; |
| } |
| |
| /* override maxstale if must-revalidate, proxy-revalidate or s-maxage */ |
| if (maxstale && (h->cache_obj->info.control.must_revalidate |
| || h->cache_obj->info.control.proxy_revalidate || smaxage != -1)) { |
| maxstale = 0; |
| } |
| |
| /* handle expiration */ |
| if (((maxage != -1) && (age < (maxage + maxstale - minfresh))) || |
| ((smaxage == -1) && (maxage == -1) && |
| (info->expire != APR_DATE_BAD) && |
| (age < (apr_time_sec(info->expire - info->date) + maxstale - minfresh)))) { |
| |
| warn_head = apr_table_get(h->resp_hdrs, "Warning"); |
| |
| /* it's fresh darlings... */ |
| /* set age header on response */ |
| apr_table_set(h->resp_hdrs, "Age", |
| apr_psprintf(r->pool, "%lu", (unsigned long)age)); |
| |
| /* add warning if maxstale overrode freshness calculation */ |
| if (!(((maxage != -1) && age < maxage) || |
| (info->expire != APR_DATE_BAD && |
| (apr_time_sec(info->expire - info->date)) > age))) { |
| /* make sure we don't stomp on a previous warning */ |
| if ((warn_head == NULL) || |
| ((warn_head != NULL) && (ap_strstr_c(warn_head, "110") == NULL))) { |
| apr_table_mergen(h->resp_hdrs, "Warning", |
| "110 Response is stale"); |
| } |
| } |
| |
| /* |
| * If none of Expires, Cache-Control: max-age, or Cache-Control: |
| * s-maxage appears in the response, and the response header age |
| * calculated is more than 24 hours add the warning 113 |
| */ |
| if ((maxage_cresp == -1) && (smaxage == -1) && (apr_table_get( |
| h->resp_hdrs, "Expires") == NULL) && (age > 86400)) { |
| |
| /* Make sure we don't stomp on a previous warning, and don't dup |
| * a 113 marning that is already present. Also, make sure to add |
| * the new warning to the correct *headers_out location. |
| */ |
| if ((warn_head == NULL) || |
| ((warn_head != NULL) && (ap_strstr_c(warn_head, "113") == NULL))) { |
| apr_table_mergen(h->resp_hdrs, "Warning", |
| "113 Heuristic expiration"); |
| } |
| } |
| return 1; /* Cache object is fresh (enough) */ |
| } |
| |
| /* |
| * At this point we are stale, but: if we are under load, we may let |
| * a significant number of stale requests through before the first |
| * stale request successfully revalidates itself, causing a sudden |
| * unexpected thundering herd which in turn brings angst and drama. |
| * |
| * So. |
| * |
| * We want the first stale request to go through as normal. But the |
| * second and subsequent request, we must pretend to be fresh until |
| * the first request comes back with either new content or confirmation |
| * that the stale content is still fresh. |
| * |
| * To achieve this, we create a very simple file based lock based on |
| * the key of the cached object. We attempt to open the lock file with |
| * exclusive write access. If we succeed, woohoo! we're first, and we |
| * follow the stale path to the backend server. If we fail, oh well, |
| * we follow the fresh path, and avoid being a thundering herd. |
| * |
| * The lock lives only as long as the stale request that went on ahead. |
| * If the request succeeds, the lock is deleted. If the request fails, |
| * the lock is deleted, and another request gets to make a new lock |
| * and try again. |
| * |
| * At any time, a request marked "no-cache" will force a refresh, |
| * ignoring the lock, ensuring an extended lockout is impossible. |
| * |
| * A lock that exceeds a maximum age will be deleted, and another |
| * request gets to make a new lock and try again. |
| */ |
| status = cache_try_lock(conf, cache, r); |
| if (APR_SUCCESS == status) { |
| /* we obtained a lock, follow the stale path */ |
| ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00782) |
| "Cache lock obtained for stale cached URL, " |
| "revalidating entry: %s", |
| r->unparsed_uri); |
| return 0; |
| } |
| else if (APR_STATUS_IS_EEXIST(status)) { |
| /* lock already exists, return stale data anyway, with a warning */ |
| ap_log_rerror(APLOG_MARK, APLOG_DEBUG, status, r, APLOGNO(00783) |
| "Cache already locked for stale cached URL, " |
| "pretend it is fresh: %s", |
| r->unparsed_uri); |
| |
| /* make sure we don't stomp on a previous warning */ |
| warn_head = apr_table_get(h->resp_hdrs, "Warning"); |
| if ((warn_head == NULL) || |
| ((warn_head != NULL) && (ap_strstr_c(warn_head, "110") == NULL))) { |
| apr_table_mergen(h->resp_hdrs, "Warning", |
| "110 Response is stale"); |
| } |
| |
| return 1; |
| } |
| else { |
| /* some other error occurred, just treat the object as stale */ |
| ap_log_rerror(APLOG_MARK, APLOG_DEBUG, status, r, APLOGNO(00784) |
| "Attempt to obtain a cache lock for stale " |
| "cached URL failed, revalidating entry anyway: %s", |
| r->unparsed_uri); |
| return 0; |
| } |
| |
| } |
| |
| /* return each comma separated token, one at a time */ |
| CACHE_DECLARE(const char *)ap_cache_tokstr(apr_pool_t *p, const char *list, |
| const char **str) |
| { |
| apr_size_t i; |
| const char *s; |
| |
| s = ap_strchr_c(list, ','); |
| if (s != NULL) { |
| i = s - list; |
| do |
| s++; |
| while (apr_isspace(*s)) |
| ; /* noop */ |
| } |
| else |
| i = strlen(list); |
| |
| while (i > 0 && apr_isspace(list[i - 1])) |
| i--; |
| |
| *str = s; |
| if (i) |
| return apr_pstrndup(p, list, i); |
| else |
| return NULL; |
| } |
| |
| /* |
| * Converts apr_time_t expressed as hex digits to |
| * a true apr_time_t. |
| */ |
| CACHE_DECLARE(apr_time_t) ap_cache_hex2usec(const char *x) |
| { |
| int i, ch; |
| apr_time_t j; |
| for (i = 0, j = 0; i < sizeof(j) * 2; i++) { |
| ch = x[i]; |
| j <<= 4; |
| if (apr_isdigit(ch)) |
| j |= ch - '0'; |
| else if (apr_isupper(ch)) |
| j |= ch - ('A' - 10); |
| else |
| j |= ch - ('a' - 10); |
| } |
| return j; |
| } |
| |
| /* |
| * Converts apr_time_t to apr_time_t expressed as hex digits. |
| */ |
| CACHE_DECLARE(void) ap_cache_usec2hex(apr_time_t j, char *y) |
| { |
| int i, ch; |
| |
| for (i = (sizeof(j) * 2)-1; i >= 0; i--) { |
| ch = (int)(j & 0xF); |
| j >>= 4; |
| if (ch >= 10) |
| y[i] = ch + ('A' - 10); |
| else |
| y[i] = ch + '0'; |
| } |
| y[sizeof(j) * 2] = '\0'; |
| } |
| |
| static void cache_hash(const char *it, char *val, int ndepth, int nlength) |
| { |
| apr_md5_ctx_t context; |
| unsigned char digest[16]; |
| char tmp[22]; |
| int i, k, d; |
| unsigned int x; |
| static const char enc_table[64] = |
| "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_@"; |
| |
| apr_md5_init(&context); |
| apr_md5_update(&context, (const unsigned char *) it, strlen(it)); |
| apr_md5_final(digest, &context); |
| |
| /* encode 128 bits as 22 characters, using a modified uuencoding |
| * the encoding is 3 bytes -> 4 characters* i.e. 128 bits is |
| * 5 x 3 bytes + 1 byte -> 5 * 4 characters + 2 characters |
| */ |
| for (i = 0, k = 0; i < 15; i += 3) { |
| x = (digest[i] << 16) | (digest[i + 1] << 8) | digest[i + 2]; |
| tmp[k++] = enc_table[x >> 18]; |
| tmp[k++] = enc_table[(x >> 12) & 0x3f]; |
| tmp[k++] = enc_table[(x >> 6) & 0x3f]; |
| tmp[k++] = enc_table[x & 0x3f]; |
| } |
| |
| /* one byte left */ |
| x = digest[15]; |
| tmp[k++] = enc_table[x >> 2]; /* use up 6 bits */ |
| tmp[k++] = enc_table[(x << 4) & 0x3f]; |
| |
| /* now split into directory levels */ |
| for (i = k = d = 0; d < ndepth; ++d) { |
| memcpy(&val[i], &tmp[k], nlength); |
| k += nlength; |
| val[i + nlength] = '/'; |
| i += nlength + 1; |
| } |
| memcpy(&val[i], &tmp[k], 22 - k); |
| val[i + 22 - k] = '\0'; |
| } |
| |
| CACHE_DECLARE(char *)ap_cache_generate_name(apr_pool_t *p, int dirlevels, |
| int dirlength, const char *name) |
| { |
| char hashfile[66]; |
| cache_hash(name, hashfile, dirlevels, dirlength); |
| return apr_pstrdup(p, hashfile); |
| } |
| |
| /** |
| * String tokenizer that ignores separator characters within quoted strings |
| * and escaped characters, as per RFC2616 section 2.2. |
| */ |
| char *cache_strqtok(char *str, const char *sep, char **last) |
| { |
| char *token; |
| int quoted = 0; |
| |
| if (!str) { /* subsequent call */ |
| str = *last; /* start where we left off */ |
| } |
| |
| if (!str) { /* no more tokens */ |
| return NULL; |
| } |
| |
| /* skip characters in sep (will terminate at '\0') */ |
| while (*str && ap_strchr_c(sep, *str)) { |
| ++str; |
| } |
| |
| if (!*str) { /* no more tokens */ |
| return NULL; |
| } |
| |
| token = str; |
| |
| /* skip valid token characters to terminate token and |
| * prepare for the next call (will terminate at '\0) |
| * on the way, ignore all quoted strings, and within |
| * quoted strings, escaped characters. |
| */ |
| *last = token; |
| while (**last) { |
| if (!quoted) { |
| if (**last == '\"' && !ap_strchr_c(sep, '\"')) { |
| quoted = 1; |
| ++*last; |
| } |
| else if (!ap_strchr_c(sep, **last)) { |
| ++*last; |
| } |
| else { |
| break; |
| } |
| } |
| else { |
| if (**last == '\"') { |
| quoted = 0; |
| ++*last; |
| } |
| else if (**last == '\\') { |
| ++*last; |
| if (**last) { |
| ++*last; |
| } |
| } |
| else { |
| ++*last; |
| } |
| } |
| } |
| |
| if (**last) { |
| **last = '\0'; |
| ++*last; |
| } |
| |
| return token; |
| } |
| |
| /** |
| * Parse the Cache-Control and Pragma headers in one go, marking |
| * which tokens appear within the header. Populate the structure |
| * passed in. |
| */ |
| int ap_cache_control(request_rec *r, cache_control_t *cc, |
| const char *cc_header, const char *pragma_header, apr_table_t *headers) |
| { |
| char *last; |
| |
| if (cc->parsed) { |
| return cc->cache_control || cc->pragma; |
| } |
| |
| cc->parsed = 1; |
| cc->max_age_value = -1; |
| cc->max_stale_value = -1; |
| cc->min_fresh_value = -1; |
| cc->s_maxage_value = -1; |
| |
| if (pragma_header) { |
| char *header = apr_pstrdup(r->pool, pragma_header); |
| const char *token = cache_strqtok(header, CACHE_SEPARATOR, &last); |
| while (token) { |
| if (!ap_cstr_casecmp(token, "no-cache")) { |
| cc->no_cache = 1; |
| } |
| token = cache_strqtok(NULL, CACHE_SEPARATOR, &last); |
| } |
| cc->pragma = 1; |
| } |
| |
| if (cc_header) { |
| char *endp; |
| apr_off_t offt; |
| char *header = apr_pstrdup(r->pool, cc_header); |
| const char *token = cache_strqtok(header, CACHE_SEPARATOR, &last); |
| while (token) { |
| switch (token[0]) { |
| case 'n': |
| case 'N': { |
| if (!ap_cstr_casecmpn(token, "no-cache", 8)) { |
| if (token[8] == '=') { |
| cc->no_cache_header = 1; |
| } |
| else if (!token[8]) { |
| cc->no_cache = 1; |
| } |
| } |
| else if (!ap_cstr_casecmp(token, "no-store")) { |
| cc->no_store = 1; |
| } |
| else if (!ap_cstr_casecmp(token, "no-transform")) { |
| cc->no_transform = 1; |
| } |
| break; |
| } |
| case 'm': |
| case 'M': { |
| if (!ap_cstr_casecmpn(token, "max-age", 7)) { |
| if (token[7] == '=' |
| && !apr_strtoff(&offt, token + 8, &endp, 10) |
| && endp > token + 8 && !*endp) { |
| cc->max_age = 1; |
| cc->max_age_value = offt; |
| } |
| } |
| else if (!ap_cstr_casecmp(token, "must-revalidate")) { |
| cc->must_revalidate = 1; |
| } |
| else if (!ap_cstr_casecmpn(token, "max-stale", 9)) { |
| if (token[9] == '=' |
| && !apr_strtoff(&offt, token + 10, &endp, 10) |
| && endp > token + 10 && !*endp) { |
| cc->max_stale = 1; |
| cc->max_stale_value = offt; |
| } |
| else if (!token[9]) { |
| cc->max_stale = 1; |
| cc->max_stale_value = -1; |
| } |
| } |
| else if (!ap_cstr_casecmpn(token, "min-fresh", 9)) { |
| if (token[9] == '=' |
| && !apr_strtoff(&offt, token + 10, &endp, 10) |
| && endp > token + 10 && !*endp) { |
| cc->min_fresh = 1; |
| cc->min_fresh_value = offt; |
| } |
| } |
| break; |
| } |
| case 'o': |
| case 'O': { |
| if (!ap_cstr_casecmp(token, "only-if-cached")) { |
| cc->only_if_cached = 1; |
| } |
| break; |
| } |
| case 'p': |
| case 'P': { |
| if (!ap_cstr_casecmp(token, "public")) { |
| cc->public = 1; |
| } |
| else if (!ap_cstr_casecmpn(token, "private", 7)) { |
| if (token[7] == '=') { |
| cc->private_header = 1; |
| } |
| else if (!token[7]) { |
| cc->private = 1; |
| } |
| } |
| else if (!ap_cstr_casecmp(token, "proxy-revalidate")) { |
| cc->proxy_revalidate = 1; |
| } |
| break; |
| } |
| case 's': |
| case 'S': { |
| if (!ap_cstr_casecmpn(token, "s-maxage", 8)) { |
| if (token[8] == '=' |
| && !apr_strtoff(&offt, token + 9, &endp, 10) |
| && endp > token + 9 && !*endp) { |
| cc->s_maxage = 1; |
| cc->s_maxage_value = offt; |
| } |
| } |
| break; |
| } |
| } |
| token = cache_strqtok(NULL, CACHE_SEPARATOR, &last); |
| } |
| cc->cache_control = 1; |
| } |
| |
| return (cc_header != NULL || pragma_header != NULL); |
| } |
| |
| /** |
| * Parse the Cache-Control, identifying and removing headers that |
| * exist as tokens after the no-cache and private tokens. |
| */ |
| static int cache_control_remove(request_rec *r, const char *cc_header, |
| apr_table_t *headers) |
| { |
| char *last, *slast; |
| int found = 0; |
| |
| if (cc_header) { |
| char *header = apr_pstrdup(r->pool, cc_header); |
| char *token = cache_strqtok(header, CACHE_SEPARATOR, &last); |
| while (token) { |
| switch (token[0]) { |
| case 'n': |
| case 'N': { |
| if (!ap_cstr_casecmpn(token, "no-cache", 8)) { |
| if (token[8] == '=') { |
| const char *header = cache_strqtok(token + 9, |
| CACHE_SEPARATOR "\"", &slast); |
| while (header) { |
| apr_table_unset(headers, header); |
| header = cache_strqtok(NULL, CACHE_SEPARATOR "\"", |
| &slast); |
| } |
| found = 1; |
| } |
| break; |
| } |
| break; |
| } |
| case 'p': |
| case 'P': { |
| if (!ap_cstr_casecmpn(token, "private", 7)) { |
| if (token[7] == '=') { |
| const char *header = cache_strqtok(token + 8, |
| CACHE_SEPARATOR "\"", &slast); |
| while (header) { |
| apr_table_unset(headers, header); |
| header = cache_strqtok(NULL, CACHE_SEPARATOR "\"", |
| &slast); |
| } |
| found = 1; |
| } |
| } |
| break; |
| } |
| } |
| token = cache_strqtok(NULL, CACHE_SEPARATOR, &last); |
| } |
| } |
| |
| return found; |
| } |
| |
| /* |
| * Create a new table consisting of those elements from an |
| * headers table that are allowed to be stored in a cache. |
| */ |
| CACHE_DECLARE(apr_table_t *)ap_cache_cacheable_headers(apr_pool_t *pool, |
| apr_table_t *t, |
| server_rec *s) |
| { |
| cache_server_conf *conf; |
| char **header; |
| int i; |
| apr_table_t *headers_out; |
| |
| /* Short circuit the common case that there are not |
| * (yet) any headers populated. |
| */ |
| if (t == NULL) { |
| return apr_table_make(pool, 10); |
| }; |
| |
| /* Make a copy of the headers, and remove from |
| * the copy any hop-by-hop headers, as defined in Section |
| * 13.5.1 of RFC 2616 |
| */ |
| headers_out = apr_table_copy(pool, t); |
| |
| apr_table_unset(headers_out, "Connection"); |
| apr_table_unset(headers_out, "Keep-Alive"); |
| apr_table_unset(headers_out, "Proxy-Authenticate"); |
| apr_table_unset(headers_out, "Proxy-Authorization"); |
| apr_table_unset(headers_out, "TE"); |
| apr_table_unset(headers_out, "Trailers"); |
| apr_table_unset(headers_out, "Transfer-Encoding"); |
| apr_table_unset(headers_out, "Upgrade"); |
| |
| conf = (cache_server_conf *)ap_get_module_config(s->module_config, |
| &cache_module); |
| |
| /* Remove the user defined headers set with CacheIgnoreHeaders. |
| * This may break RFC 2616 compliance on behalf of the administrator. |
| */ |
| header = (char **)conf->ignore_headers->elts; |
| for (i = 0; i < conf->ignore_headers->nelts; i++) { |
| apr_table_unset(headers_out, header[i]); |
| } |
| return headers_out; |
| } |
| |
| /* |
| * Create a new table consisting of those elements from an input |
| * headers table that are allowed to be stored in a cache. |
| */ |
| CACHE_DECLARE(apr_table_t *)ap_cache_cacheable_headers_in(request_rec *r) |
| { |
| return ap_cache_cacheable_headers(r->pool, r->headers_in, r->server); |
| } |
| |
| /* |
| * Create a new table consisting of those elements from an output |
| * headers table that are allowed to be stored in a cache; |
| * ensure there is a content type and capture any errors. |
| */ |
| CACHE_DECLARE(apr_table_t *)ap_cache_cacheable_headers_out(request_rec *r) |
| { |
| apr_table_t *headers_out; |
| |
| headers_out = ap_cache_cacheable_headers(r->pool, |
| cache_merge_headers_out(r), |
| r->server); |
| |
| cache_control_remove(r, |
| cache_table_getm(r->pool, headers_out, "Cache-Control"), |
| headers_out); |
| |
| return headers_out; |
| } |
| |
| apr_table_t *cache_merge_headers_out(request_rec *r) |
| { |
| apr_table_t *headers_out; |
| |
| headers_out = apr_table_overlay(r->pool, r->headers_out, |
| r->err_headers_out); |
| |
| if (r->content_type |
| && !apr_table_get(headers_out, "Content-Type")) { |
| const char *ctype = ap_make_content_type(r, r->content_type); |
| if (ctype) { |
| apr_table_setn(headers_out, "Content-Type", ctype); |
| } |
| } |
| |
| if (r->content_encoding |
| && !apr_table_get(headers_out, "Content-Encoding")) { |
| apr_table_setn(headers_out, "Content-Encoding", |
| r->content_encoding); |
| } |
| |
| return headers_out; |
| } |
| |
| typedef struct |
| { |
| apr_pool_t *p; |
| const char *first; |
| apr_array_header_t *merged; |
| } cache_table_getm_t; |
| |
| static int cache_table_getm_do(void *v, const char *key, const char *val) |
| { |
| cache_table_getm_t *state = (cache_table_getm_t *) v; |
| |
| if (!state->first) { |
| /** |
| * The most common case is a single header, and this is covered by |
| * a fast path that doesn't allocate any memory. On the second and |
| * subsequent header, an array is created and the array concatenated |
| * together to form the final value. |
| */ |
| state->first = val; |
| } |
| else { |
| const char **elt; |
| if (!state->merged) { |
| state->merged = apr_array_make(state->p, 10, sizeof(const char *)); |
| elt = apr_array_push(state->merged); |
| *elt = state->first; |
| } |
| elt = apr_array_push(state->merged); |
| *elt = val; |
| } |
| return 1; |
| } |
| |
| const char *cache_table_getm(apr_pool_t *p, const apr_table_t *t, |
| const char *key) |
| { |
| cache_table_getm_t state; |
| |
| state.p = p; |
| state.first = NULL; |
| state.merged = NULL; |
| |
| apr_table_do(cache_table_getm_do, &state, t, key, NULL); |
| |
| if (!state.first) { |
| return NULL; |
| } |
| else if (!state.merged) { |
| return state.first; |
| } |
| else { |
| return apr_array_pstrcat(p, state.merged, ','); |
| } |
| } |
