/* 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. */ /** * @file cache_util.h * @brief Cache Storage Functions * * @defgroup Cache_util Cache Utility Functions * @ingroup MOD_CACHE * @{ */ #ifndef CACHE_UTIL_H #define CACHE_UTIL_H #ifdef __cplusplus extern "C" { #endif #include "mod_cache.h" #include "apr_hooks.h" #include "apr.h" #include "apr_lib.h" #include "apr_strings.h" #include "apr_buckets.h" #include "apr_md5.h" #include "apr_pools.h" #include "apr_strings.h" #include "apr_optional.h" #define APR_WANT_STRFUNC #include "apr_want.h" #include "httpd.h" #include "http_config.h" #include "ap_config.h" #include "http_core.h" #include "http_protocol.h" #include "http_request.h" #include "http_vhost.h" #include "http_main.h" #include "http_log.h" #include "http_connection.h" #include "util_filter.h" #include "apr_uri.h" #ifdef HAVE_NETDB_H #include #endif #ifdef HAVE_SYS_SOCKET_H #include #endif #ifdef HAVE_NETINET_IN_H #include #endif #ifdef HAVE_ARPA_INET_H #include #endif #include "apr_atomic.h" #ifndef MAX #define MAX(a,b) ((a) > (b) ? (a) : (b)) #endif #ifndef MIN #define MIN(a,b) ((a) < (b) ? (a) : (b)) #endif #define MSEC_ONE_DAY ((apr_time_t)(86400*APR_USEC_PER_SEC)) /* one day, in microseconds */ #define MSEC_ONE_HR ((apr_time_t)(3600*APR_USEC_PER_SEC)) /* one hour, in microseconds */ #define MSEC_ONE_MIN ((apr_time_t)(60*APR_USEC_PER_SEC)) /* one minute, in microseconds */ #define MSEC_ONE_SEC ((apr_time_t)(APR_USEC_PER_SEC)) /* one second, in microseconds */ #define DEFAULT_CACHE_MAXEXPIRE MSEC_ONE_DAY #define DEFAULT_CACHE_MINEXPIRE 0 #define DEFAULT_CACHE_EXPIRE MSEC_ONE_HR #define DEFAULT_CACHE_LMFACTOR (0.1) #define DEFAULT_CACHE_MAXAGE 5 #define DEFAULT_X_CACHE 0 #define DEFAULT_X_CACHE_DETAIL 0 #define DEFAULT_CACHE_STALE_ON_ERROR 1 #define DEFAULT_CACHE_LOCKPATH "/mod_cache-lock" #define CACHE_LOCKNAME_KEY "mod_cache-lockname" #define CACHE_LOCKFILE_KEY "mod_cache-lockfile" #define CACHE_CTX_KEY "mod_cache-ctx" #define CACHE_SEPARATOR ", \t" /** * cache_util.c */ struct cache_enable { apr_uri_t url; const char *type; apr_size_t pathlen; }; struct cache_disable { apr_uri_t url; apr_size_t pathlen; }; /* static information about the local cache */ typedef struct { apr_array_header_t *cacheenable; /* URLs to cache */ apr_array_header_t *cachedisable; /* URLs not to cache */ /** store the headers that should not be stored in the cache */ apr_array_header_t *ignore_headers; /** store the identifiers that should not be used for key calculation */ apr_array_header_t *ignore_session_id; const char *lockpath; apr_time_t lockmaxage; apr_uri_t *base_uri; /** ignore client's requests for uncached responses */ unsigned int ignorecachecontrol:1; /** ignore query-string when caching */ unsigned int ignorequerystring:1; /** run within the quick handler */ unsigned int quick:1; /* thundering herd lock */ unsigned int lock:1; unsigned int x_cache:1; unsigned int x_cache_detail:1; /* flag if CacheIgnoreHeader has been set */ #define CACHE_IGNORE_HEADERS_SET 1 #define CACHE_IGNORE_HEADERS_UNSET 0 unsigned int ignore_headers_set:1; /* flag if CacheIgnoreURLSessionIdentifiers has been set */ #define CACHE_IGNORE_SESSION_ID_SET 1 #define CACHE_IGNORE_SESSION_ID_UNSET 0 unsigned int ignore_session_id_set:1; unsigned int base_uri_set:1; unsigned int ignorecachecontrol_set:1; unsigned int ignorequerystring_set:1; unsigned int quick_set:1; unsigned int lock_set:1; unsigned int lockpath_set:1; unsigned int lockmaxage_set:1; unsigned int x_cache_set:1; unsigned int x_cache_detail_set:1; } cache_server_conf; typedef struct { /* Minimum time to keep cached files in msecs */ apr_time_t minex; /* Maximum time to keep cached files in msecs */ apr_time_t maxex; /* default time to keep cached file in msecs */ apr_time_t defex; /* factor for estimating expires date */ double factor; /* cache enabled for this location */ apr_array_header_t *cacheenable; /* cache disabled for this location */ unsigned int disable:1; /* set X-Cache headers */ unsigned int x_cache:1; unsigned int x_cache_detail:1; /* serve stale on error */ unsigned int stale_on_error:1; /** ignore the last-modified header when deciding to cache this request */ unsigned int no_last_mod_ignore:1; /** ignore expiration date from server */ unsigned int store_expired:1; /** ignore Cache-Control: private header from server */ unsigned int store_private:1; /** ignore Cache-Control: no-store header from client or server */ unsigned int store_nostore:1; unsigned int minex_set:1; unsigned int maxex_set:1; unsigned int defex_set:1; unsigned int factor_set:1; unsigned int x_cache_set:1; unsigned int x_cache_detail_set:1; unsigned int stale_on_error_set:1; unsigned int no_last_mod_ignore_set:1; unsigned int store_expired_set:1; unsigned int store_private_set:1; unsigned int store_nostore_set:1; unsigned int enable_set:1; unsigned int disable_set:1; /* treat maxex as hard limit */ unsigned int hardmaxex:1; unsigned int hardmaxex_set:1; } cache_dir_conf; /* A linked-list of authn providers. */ typedef struct cache_provider_list cache_provider_list; struct cache_provider_list { const char *provider_name; const cache_provider *provider; cache_provider_list *next; }; /* per request cache information */ typedef struct { cache_provider_list *providers; /* possible cache providers */ const cache_provider *provider; /* current cache provider */ const char *provider_name; /* current cache provider name */ int fresh; /* is the entity fresh? */ cache_handle_t *handle; /* current cache handle */ cache_handle_t *stale_handle; /* stale cache handle */ apr_table_t *stale_headers; /* original request headers. */ int in_checked; /* CACHE_SAVE must cache the entity */ int block_response; /* CACHE_SAVE must block response. */ apr_bucket_brigade *saved_brigade; /* copy of partial response */ apr_off_t saved_size; /* length of saved_brigade */ apr_time_t exp; /* expiration */ apr_time_t lastmod; /* last-modified time */ cache_info *info; /* current cache info */ ap_filter_t *save_filter; /* Enable us to restore the filter on error */ ap_filter_t *remove_url_filter; /* Enable us to remove the filter */ const char *key; /* The cache key created for this * request */ apr_off_t size; /* the content length from the headers, or -1 */ apr_bucket_brigade *out; /* brigade to reuse for upstream responses */ cache_control_t control_in; /* cache control incoming */ } cache_request_rec; /** * Check the whether the request allows a cached object to be served as per RFC2616 * section 14.9.4 (Cache Revalidation and Reload Controls) * @param cache cache_request_rec * @param r request_rec * @return 0 ==> cache object may not be served, 1 ==> cache object may be served */ int ap_cache_check_no_cache(cache_request_rec *cache, request_rec *r); /** * Check the whether the request allows a cached object to be stored as per RFC2616 * section 14.9.2 (What May be Stored by Caches) * @param cache cache_request_rec * @param r request_rec * @return 0 ==> cache object may not be served, 1 ==> cache object may be served */ int ap_cache_check_no_store(cache_request_rec *cache, request_rec *r); /** * Check the freshness of the cache object per RFC2616 section 13.2 (Expiration Model) * @param h cache_handle_t * @param cache cache_request_rec * @param r request_rec * @return 0 ==> cache object is stale, 1 ==> cache object is fresh */ int cache_check_freshness(cache_handle_t *h, cache_request_rec *cache, request_rec *r); /** * 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_EEXISTS, 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 is 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); /** * 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); cache_provider_list *cache_get_providers(request_rec *r, cache_server_conf *conf); /** * Get a value from a table, where the table may contain multiple * values for a given key. * * When the table contains a single value, that value is returned * unchanged. * * When the table contains two or more values for a key, all values * for the key are returned, separated by commas. */ const char *cache_table_getm(apr_pool_t *p, const apr_table_t *t, const char *key); /** * 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); /** * Merge err_headers_out into headers_out and add request's Content-Type and * Content-Encoding if available. */ apr_table_t *cache_merge_headers_out(request_rec *r); /** * Return whether to use request's path/query from early stage (r->parsed_uri) * or the current/rewritable ones (r->uri/r->args). */ int cache_use_early_url(request_rec *r); #ifdef __cplusplus } #endif #endif /* !CACHE_UTIL_H */ /** @} */