modules/cache/cache_util.c

	cache_util.c revision 4a315156bb61dcbae4d7b9769751832362fd148c
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding/* Licensed to the Apache Software Foundation (ASF) under one or more
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding * contributor license agreements.  See the NOTICE file distributed with
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding * this work for additional information regarding copyright ownership.
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding * The ASF licenses this file to You under the Apache License, Version 2.0
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding * (the "License"); you may not use this file except in compliance with
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * the License.  You may obtain a copy of the License at
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding *     http://www.apache.org/licenses/LICENSE-2.0
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * Unless required by applicable law or agreed to in writing, software
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * distributed under the License is distributed on an "AS IS" BASIS,
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * See the License for the specific language governing permissions and
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * limitations under the License.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding#include "mod_cache.h"
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding#include <ap_provider.h>
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding/* -------------------------------------------------------------- */
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffieldingextern APR_OPTIONAL_FN_TYPE(ap_cache_generate_key) *cache_generate_key;
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fieldingextern module AP_MODULE_DECLARE_DATA cache_module;
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding/* Determine if "url" matches the hostname, scheme and port and path
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding * in "filter". All but the path comparisons are case-insensitive.
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fieldingstatic int uri_meets_conditions(apr_uri_t filter, int pathlen, apr_uri_t url)
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding{
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding    /* Compare the hostnames */
64185f9824e42f21ca7b9ae6c004484215c031a7rbb    if(filter.hostname) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        if (!url.hostname) {
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding            return 0;
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding        }
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding        else if (strcasecmp(filter.hostname, url.hostname)) {
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding            return 0;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        }
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding    }
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding    /* Compare the schemes */
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding    if(filter.scheme) {
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding        if (!url.scheme) {
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding            return 0;
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        else if (strcasecmp(filter.scheme, url.scheme)) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            return 0;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        }
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding    }
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding    /* Compare the ports */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if(filter.port_str) {
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding        if (url.port_str && filter.port != url.port) {
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding            return 0;
7e79e8fd53348f9fc6e8009a4a2522425ab6f08ffielding        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        /* NOTE:  ap_port_of_scheme will return 0 if given NULL input */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        else if (filter.port != apr_uri_port_of_scheme(url.scheme)) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            return 0;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    else if(url.port_str && filter.scheme) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        if (apr_uri_port_of_scheme(filter.scheme) == url.port) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            return 0;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        }
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein    }
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein    /* For HTTP caching purposes, an empty (NULL) path is equivalent to
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein     * a single "/" path. RFCs 3986/2396
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein     */
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein    if (!url.path) {
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein        if (*filter.path == '/' && pathlen == 1) {
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein            return 1;
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein        }
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein        else {
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein            return 0;
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein    /* Url has met all of the filter conditions so far, determine
b0f20a4a26bcfa85724b1c2e5ec6a077f12ef44crbb     * if the paths match.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    return !strncmp(filter.path, url.path, pathlen);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding}
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fieldingCACHE_DECLARE(cache_provider_list *)ap_cache_get_providers(request_rec *r,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                                                  cache_server_conf *conf,
d41217398f0e1031adbb6f5bd37f45737c805deftrawick                                                  apr_uri_t uri)
d41217398f0e1031adbb6f5bd37f45737c805deftrawick{
d41217398f0e1031adbb6f5bd37f45737c805deftrawick    cache_provider_list *providers = NULL;
49d54ef49e3f7620260795178f3c6ba6ef3f21e9bjh    int i;
49d54ef49e3f7620260795178f3c6ba6ef3f21e9bjh
49d54ef49e3f7620260795178f3c6ba6ef3f21e9bjh    /* loop through all the cacheenable entries */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    for (i = 0; i < conf->cacheenable->nelts; i++) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        struct cache_enable *ent =
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                                (struct cache_enable *)conf->cacheenable->elts;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        if (uri_meets_conditions(ent[i].url, ent[i].pathlen, uri)) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            /* Fetch from global config and add to the list. */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            cache_provider *provider;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            provider = ap_lookup_provider(CACHE_PROVIDER_GROUP, ent[i].type,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                                          "0");
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            if (!provider) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                /* Log an error! */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            else {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                cache_provider_list *newp;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                newp = apr_pcalloc(r->pool, sizeof(cache_provider_list));
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                newp->provider_name = ent[i].type;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                newp->provider = provider;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                if (!providers) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                    providers = newp;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                else {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                    cache_provider_list *last = providers;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                    while (last->next) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                        last = last->next;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                    last->next = newp;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    /* then loop through all the cachedisable entries
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * Looking for urls that contain the full cachedisable url and possibly
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * more.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * This means we are disabling cachedisable url and below...
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    for (i = 0; i < conf->cachedisable->nelts; i++) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        struct cache_disable *ent =
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                               (struct cache_disable *)conf->cachedisable->elts;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        if (uri_meets_conditions(ent[i].url, ent[i].pathlen, uri)) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            /* Stop searching now. */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            return NULL;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    return providers;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding}
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding/* do a HTTP/1.1 age calculation */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fieldingCACHE_DECLARE(apr_int64_t) ap_cache_current_age(cache_info *info,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                                                const apr_time_t age_value,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                                                apr_time_t now)
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding{
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    apr_time_t apparent_age, corrected_received_age, response_delay,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding               corrected_initial_age, resident_time, current_age,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding               age_value_usec;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    age_value_usec = apr_time_from_sec(age_value);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    /* Perform an HTTP/1.1 age calculation. (RFC2616 13.2.3) */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    apparent_age = MAX(0, info->response_time - info->date);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    corrected_received_age = MAX(apparent_age, age_value_usec);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    response_delay = info->response_time - info->request_time;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    corrected_initial_age = corrected_received_age + response_delay;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    resident_time = now - info->response_time;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    current_age = corrected_initial_age + resident_time;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    return apr_time_sec(current_age);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding}
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding/**
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * Try obtain a cache wide lock on the given cache key.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * If we return APR_SUCCESS, we obtained the lock, and we are clear to
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * proceed to the backend. If we return APR_EEXISTS, then the lock is
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * already locked, someone else has gone to refresh the backend data
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * already, so we must return stale data with a warning in the mean
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * time. If we return anything else, then something has gone pear
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * shaped, and we allow the request through to the backend regardless.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding *
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm * This lock is created from the request pool, meaning that should
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm * something go wrong and the lock isn't deleted on return of the
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * request headers from the backend for whatever reason, at worst the
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * lock will be cleaned up when the request dies or finishes.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * If something goes truly bananas and the lock isn't deleted when the
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * request dies, the lock will be trashed when its max-age is reached,
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb * or when a request arrives containing a Cache-Control: no-cache. At
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm * no point is it possible for this lock to permanently deny access to
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm * the backend.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fieldingCACHE_DECLARE(apr_status_t) ap_cache_try_lock(cache_server_conf *conf,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        request_rec *r, char *key) {
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    apr_status_t status;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    const char *lockname;
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    const char *path;
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    char dir[5];
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    apr_time_t now = apr_time_now();
a952e0c6ece342d88f2bc04e20dcfc563398eed3rbb    apr_finfo_t finfo;
ec727afb817df0e5202135278c0d2902923cc980stoddard    apr_file_t *lockfile;
ec727afb817df0e5202135278c0d2902923cc980stoddard    void *dummy;
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    finfo.mtime = 0;
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    if (!conf || !conf->lock || !conf->lockpath) {
fa4e5ac791dd1c84df616b28d4ee9751efe9c64frbb        /* no locks configured, leave */
fa4e5ac791dd1c84df616b28d4ee9751efe9c64frbb        return APR_SUCCESS;
fa4e5ac791dd1c84df616b28d4ee9751efe9c64frbb    }
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    /* lock already obtained earlier? if so, success */
db2ef76dc744b13b9a9929ebb9e6f94712a81717rbb    apr_pool_userdata_get(&dummy, CACHE_LOCKFILE_KEY, r->pool);
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein    if (dummy) {
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein        return APR_SUCCESS;
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    }
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    /* create the key if it doesn't exist */
20c85ca0d404e29972fb94c3d6236a264d1c77abstoddard    if (!key) {
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb        cache_generate_key(r, r->pool, &key);
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    }
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    /* create a hashed filename from the key, and save it for later */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    lockname = ap_cache_generate_name(r->pool, 0, 0, key);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    /* lock files represent discrete just-went-stale URLs "in flight", so
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * we support a simple two level directory structure, more is overkill.
061c3874622b67beff724876b9bd1b1f291f2eaafielding     */
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    dir[0] = '/';
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    dir[1] = lockname[0];
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    dir[2] = '/';
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    dir[3] = lockname[1];
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    dir[4] = 0;
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb
a952e0c6ece342d88f2bc04e20dcfc563398eed3rbb    /* make the directories */
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    path = apr_pstrcat(r->pool, conf->lockpath, dir, NULL);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (APR_SUCCESS != (status = apr_dir_make_recursive(path,
2b484455736f4c30447aa852764f53282cbeb5ddrbb            APR_UREAD|APR_UWRITE|APR_UEXECUTE, r->pool))) {
2b484455736f4c30447aa852764f53282cbeb5ddrbb        ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server,
2b484455736f4c30447aa852764f53282cbeb5ddrbb                     "Could not create a cache lock directory: %s",
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                     path);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        return status;
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    lockname = apr_pstrcat(r->pool, path, "/", lockname, NULL);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    apr_pool_userdata_set(lockname, CACHE_LOCKNAME_KEY, NULL, r->pool);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    /* is an existing lock file too old? */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    status = apr_stat(&finfo, lockname,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                APR_FINFO_MTIME | APR_FINFO_NLINK, r->pool);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (!(APR_STATUS_IS_ENOENT(status)) && APR_SUCCESS != status) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        ap_log_error(APLOG_MARK, APLOG_ERR, APR_EEXIST, r->server,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                     "Could not stat a cache lock file: %s",
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                     lockname);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        return status;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if ((status == APR_SUCCESS) && (((now - finfo.mtime) > conf->lockmaxage)
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                                  || (now < finfo.mtime))) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        ap_log_error(APLOG_MARK, APLOG_INFO, status, r->server,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                     "Cache lock file for '%s' too old, removing: %s",
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                     r->uri, lockname);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        apr_file_remove(lockname, r->pool);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    /* try obtain a lock on the file */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (APR_SUCCESS == (status = apr_file_open(&lockfile, lockname,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            APR_WRITE | APR_CREATE | APR_EXCL | APR_DELONCLOSE,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            APR_UREAD | APR_UWRITE, r->pool))) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        apr_pool_userdata_set(lockfile, CACHE_LOCKFILE_KEY, NULL, r->pool);
061c3874622b67beff724876b9bd1b1f291f2eaafielding    }
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    return status;
95ed69df3d43a7d2758720bad8950f07587bdeb9bjh
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding}
2b484455736f4c30447aa852764f53282cbeb5ddrbb
2b484455736f4c30447aa852764f53282cbeb5ddrbb/**
2b484455736f4c30447aa852764f53282cbeb5ddrbb * Remove the cache lock, if present.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * First, try to close the file handle, whose delete-on-close should
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * kill the file. Otherwise, just delete the file by name.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * If no lock name has yet been calculated, do the calculation of the
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm * lock name first before trying to delete the file.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding *
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm * If an optional bucket brigade is passed, the lock will only be
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * removed if the bucket brigade contains an EOS bucket.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding */
1ccd992d37d62c8cb2056126f2234f64ec189bfddougmCACHE_DECLARE(apr_status_t) ap_cache_remove_lock(cache_server_conf *conf,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        request_rec *r, char *key, apr_bucket_brigade *bb) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    void *dummy;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    const char *lockname;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (!conf || !conf->lock || !conf->lockpath) {
c57161db43fe4cf5a62758d7d0834675e59cad0astoddard        /* no locks configured, leave */
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        return APR_SUCCESS;
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    }
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    if (bb) {
4e1e8abb2a6e588366a4680b039b460fc5fe1ccdstoddard        apr_bucket *e;
ec727afb817df0e5202135278c0d2902923cc980stoddard        int eos_found = 0;
ec727afb817df0e5202135278c0d2902923cc980stoddard        for (e = APR_BRIGADE_FIRST(bb);
ec727afb817df0e5202135278c0d2902923cc980stoddard             e != APR_BRIGADE_SENTINEL(bb);
ec727afb817df0e5202135278c0d2902923cc980stoddard             e = APR_BUCKET_NEXT(e))
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            if (APR_BUCKET_IS_EOS(e)) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                eos_found = 1;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                break;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        }
0942697a9b5de44865676345a3828741c827efe6rbb        if (!eos_found) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            /* no eos found in brigade, don't delete anything just yet,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding             * we are not done.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding             */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            return APR_SUCCESS;
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    apr_pool_userdata_get(&dummy, CACHE_LOCKFILE_KEY, r->pool);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (dummy) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        return apr_file_close((apr_file_t *)dummy);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    apr_pool_userdata_get(&dummy, CACHE_LOCKNAME_KEY, r->pool);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    lockname = (const char *)dummy;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (!lockname) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        char dir[5];
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        /* create the key if it doesn't exist */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        if (!key) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            cache_generate_key(r, r->pool, &key);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        }
3d96ee83babeec32482c9082c9426340cee8c44dwrowe
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        /* create a hashed filename from the key, and save it for later */
ab5581cc78e9d865b0a6ab1404c53347b3276968rbb        lockname = ap_cache_generate_name(r->pool, 0, 0, key);
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm
4e1e8abb2a6e588366a4680b039b460fc5fe1ccdstoddard        /* lock files represent discrete just-went-stale URLs "in flight", so
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm         * we support a simple two level directory structure, more is overkill.
40303323ae9960bd38a0f03d2c10e897a7badd88rbb         */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        dir[0] = '/';
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        dir[1] = lockname[0];
0942697a9b5de44865676345a3828741c827efe6rbb        dir[2] = '/';
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        dir[3] = lockname[1];
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        dir[4] = 0;
3597d6b10c88c252f156fe8061b659a38dea38c2rbb
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        lockname = apr_pstrcat(r->pool, conf->lockpath, dir, "/", lockname, NULL);
a1de70bda57b72d8cc6b47ea744e0973ed424f56wrowe    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    return apr_file_remove(lockname, r->pool);
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm}
d2e443764d6855a4a06c8eb2b7708ab9b465ddeerbb
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fieldingCACHE_DECLARE(int) ap_cache_check_freshness(cache_handle_t *h,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                                            request_rec *r)
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding{
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    apr_status_t status;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    apr_int64_t age, maxage_req, maxage_cresp, maxage, smaxage, maxstale;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    apr_int64_t minfresh;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    const char *cc_cresp, *cc_req;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    const char *pragma;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    const char *agestr = NULL;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    const char *expstr = NULL;
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    char *val;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    apr_time_t age_c = 0;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    cache_info *info = &(h->cache_obj->info);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    const char *warn_head;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    cache_server_conf *conf =
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding      (cache_server_conf *)ap_get_module_config(r->server->module_config,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                                                &cache_module);
2b484455736f4c30447aa852764f53282cbeb5ddrbb
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    /*
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * We now want to check if our cached data is still fresh. This depends
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * on a few things, in this order:
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * - RFC2616 14.9.4 End to end reload, Cache-Control: no-cache. no-cache in
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * either the request or the cached response means that we must
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * revalidate the request unconditionally, overriding any expiration
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * mechanism. It's equivalent to max-age=0,must-revalidate.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * - RFC2616 14.32 Pragma: no-cache This is treated the same as
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * Cache-Control: no-cache.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * - RFC2616 14.9.3 Cache-Control: max-stale, must-revalidate,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * proxy-revalidate if the max-stale request header exists, modify the
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * stale calculations below so that an object can be at most <max-stale>
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * seconds stale before we request a revalidation, _UNLESS_ a
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * must-revalidate or proxy-revalidate cached response header exists to
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * stop us doing this.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * - RFC2616 14.9.3 Cache-Control: s-maxage the origin server specifies the
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * maximum age an object can be before it is considered stale. This
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * directive has the effect of proxy|must revalidate, which in turn means
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * simple ignore any max-stale setting.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * - RFC2616 14.9.4 Cache-Control: max-age this header can appear in both
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * requests and responses. If both are specified, the smaller of the two
2b484455736f4c30447aa852764f53282cbeb5ddrbb     * takes priority.
6db54801798f6021bb464de7b3fdcc9dc3150f7bdgaudet     *
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm     * - RFC2616 14.21 Expires: if this request header exists in the cached
10a4cdd68ef1ca0e54af296fe1d08ac00150c90bwrowe     * entity, and it's value is in the past, it has expired.
10a4cdd68ef1ca0e54af296fe1d08ac00150c90bwrowe     *
10a4cdd68ef1ca0e54af296fe1d08ac00150c90bwrowe     */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    /* This value comes from the client's initial request. */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    cc_req = apr_table_get(r->headers_in, "Cache-Control");
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    pragma = apr_table_get(r->headers_in, "Pragma");
2b484455736f4c30447aa852764f53282cbeb5ddrbb
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    if (ap_cache_liststr(NULL, pragma, "no-cache", NULL)
2b484455736f4c30447aa852764f53282cbeb5ddrbb        || ap_cache_liststr(NULL, cc_req, "no-cache", NULL)) {
2b484455736f4c30447aa852764f53282cbeb5ddrbb
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        if (!conf->ignorecachecontrol) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            /* Treat as stale, causing revalidation */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            return 0;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        ap_log_error(APLOG_MARK, APLOG_INFO, 0, r->server,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                     "Incoming request is asking for a uncached version of "
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                     "%s, but we know better and are ignoring it",
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                     r->unparsed_uri);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    /* These come from the cached entity. */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    cc_cresp = apr_table_get(h->resp_hdrs, "Cache-Control");
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    expstr = apr_table_get(h->resp_hdrs, "Expires");
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (ap_cache_liststr(NULL, cc_cresp, "no-cache", NULL)) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        /*
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding         * The cached entity contained Cache-Control: no-cache, so treat as
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding         * stale causing revalidation
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding         */
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        return 0;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if ((agestr = apr_table_get(h->resp_hdrs, "Age"))) {
fd47393e4c08a1515601cb1f1e8deddf4163e858martin        age_c = apr_atoi64(agestr);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    /* calculate age of object */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    age = ap_cache_current_age(info, age_c, r->request_time);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    /* extract s-maxage */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (cc_cresp && ap_cache_liststr(r->pool, cc_cresp, "s-maxage", &val)
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        && val != NULL) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        smaxage = apr_atoi64(val);
b0f20a4a26bcfa85724b1c2e5ec6a077f12ef44crbb    }
7041bead13293c6a2e47ae1babc35f2da1d6a749trawick    else {
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        smaxage = -1;
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    /* extract max-age from request */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (!conf->ignorecachecontrol
d2e443764d6855a4a06c8eb2b7708ab9b465ddeerbb        && cc_req && ap_cache_liststr(r->pool, cc_req, "max-age", &val)
d2e443764d6855a4a06c8eb2b7708ab9b465ddeerbb        && val != NULL) {
d2e443764d6855a4a06c8eb2b7708ab9b465ddeerbb        maxage_req = apr_atoi64(val);
d2e443764d6855a4a06c8eb2b7708ab9b465ddeerbb    }
d2e443764d6855a4a06c8eb2b7708ab9b465ddeerbb    else {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        maxage_req = -1;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm
e7daae8d2ef0165e83627188bf33655c0b8266e8wrowe    /* extract max-age from response */
e7daae8d2ef0165e83627188bf33655c0b8266e8wrowe    if (cc_cresp && ap_cache_liststr(r->pool, cc_cresp, "max-age", &val)
a1de70bda57b72d8cc6b47ea744e0973ed424f56wrowe        && val != NULL) {
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        maxage_cresp = apr_atoi64(val);
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    else {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        maxage_cresp = -1;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    /*
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * if both maxage request and response, the smaller one takes priority
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (maxage_req == -1) {
3d96ee83babeec32482c9082c9426340cee8c44dwrowe        maxage = maxage_cresp;
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    }
0942697a9b5de44865676345a3828741c827efe6rbb    else if (maxage_cresp == -1) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        maxage = maxage_req;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    else {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        maxage = MIN(maxage_req, maxage_cresp);
3597d6b10c88c252f156fe8061b659a38dea38c2rbb    }
3597d6b10c88c252f156fe8061b659a38dea38c2rbb
3597d6b10c88c252f156fe8061b659a38dea38c2rbb    /* extract max-stale */
3597d6b10c88c252f156fe8061b659a38dea38c2rbb    if (cc_req && ap_cache_liststr(r->pool, cc_req, "max-stale", &val)) {
3d96ee83babeec32482c9082c9426340cee8c44dwrowe        if(val != NULL) {
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm            maxstale = apr_atoi64(val);
3597d6b10c88c252f156fe8061b659a38dea38c2rbb        }
3597d6b10c88c252f156fe8061b659a38dea38c2rbb        else {
3597d6b10c88c252f156fe8061b659a38dea38c2rbb            /*
3597d6b10c88c252f156fe8061b659a38dea38c2rbb             * If no value is assigned to max-stale, then the client is willing
3597d6b10c88c252f156fe8061b659a38dea38c2rbb             * to accept a stale response of any age (RFC2616 14.9.3). We will
3597d6b10c88c252f156fe8061b659a38dea38c2rbb             * set it to one year in this case as this situation is somewhat
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding             * similar to a "never expires" Expires header (RFC2616 14.21)
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding             * which is set to a date one year from the time the response is
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding             * sent in this case.
3d96ee83babeec32482c9082c9426340cee8c44dwrowe             */
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm            maxstale = APR_INT64_C(86400*365);
0942697a9b5de44865676345a3828741c827efe6rbb        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    else {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        maxstale = 0;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
3597d6b10c88c252f156fe8061b659a38dea38c2rbb
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    /* extract min-fresh */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (!conf->ignorecachecontrol
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        && cc_req && ap_cache_liststr(r->pool, cc_req, "min-fresh", &val)
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        && val != NULL) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        minfresh = apr_atoi64(val);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    else {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        minfresh = 0;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    /* override maxstale if must-revalidate or proxy-revalidate */
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    if (maxstale && ((cc_cresp &&
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                      ap_cache_liststr(NULL, cc_cresp,
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                                       "must-revalidate", NULL)) ||
3a9bc6532fbe8439fc748d8ffedb87415904d16ajim                     (cc_cresp &&
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                      ap_cache_liststr(NULL, cc_cresp,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                                       "proxy-revalidate", NULL)))) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        maxstale = 0;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    /* handle expiration */
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    if (((smaxage != -1) && (age < (smaxage - minfresh))) ||
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        ((maxage != -1) && (age < (maxage + maxstale - minfresh))) ||
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        ((smaxage == -1) && (maxage == -1) &&
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding         (info->expire != APR_DATE_BAD) &&
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm         (age < (apr_time_sec(info->expire - info->date) + maxstale - minfresh)))) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        warn_head = apr_table_get(h->resp_hdrs, "Warning");
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        /* it's fresh darlings... */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        /* set age header on response */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        apr_table_set(h->resp_hdrs, "Age",
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                      apr_psprintf(r->pool, "%lu", (unsigned long)age));
061c3874622b67beff724876b9bd1b1f291f2eaafielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        /* add warning if maxstale overrode freshness calculation */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        if (!(((smaxage != -1) && age < smaxage) ||
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding              ((maxage != -1) && age < maxage) ||
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding              (info->expire != APR_DATE_BAD &&
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding               (apr_time_sec(info->expire - info->date)) > age))) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            /* make sure we don't stomp on a previous warning */
0942697a9b5de44865676345a3828741c827efe6rbb            if ((warn_head == NULL) ||
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                ((warn_head != NULL) && (ap_strstr_c(warn_head, "110") == NULL))) {
ab5581cc78e9d865b0a6ab1404c53347b3276968rbb                apr_table_merge(h->resp_hdrs, "Warning",
ab5581cc78e9d865b0a6ab1404c53347b3276968rbb                                "110 Response is stale");
ab5581cc78e9d865b0a6ab1404c53347b3276968rbb            }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        /*
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm         * If none of Expires, Cache-Control: max-age, or Cache-Control:
cf5ace98ead10d803fda70674cb4dda30fddb832trawick         * s-maxage appears in the response, and the response header age
cf5ace98ead10d803fda70674cb4dda30fddb832trawick         * calculated is more than 24 hours add the warning 113
cf5ace98ead10d803fda70674cb4dda30fddb832trawick         */
cf5ace98ead10d803fda70674cb4dda30fddb832trawick        if ((maxage_cresp == -1) && (smaxage == -1) &&
2b484455736f4c30447aa852764f53282cbeb5ddrbb            (expstr == NULL) && (age > 86400)) {
2b484455736f4c30447aa852764f53282cbeb5ddrbb
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            /* Make sure we don't stomp on a previous warning, and don't dup
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding             * a 113 marning that is already present. Also, make sure to add
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm             * the new warning to the correct *headers_out location.
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm             */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            if ((warn_head == NULL) ||
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                ((warn_head != NULL) && (ap_strstr_c(warn_head, "113") == NULL))) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                apr_table_merge(h->resp_hdrs, "Warning",
3d96ee83babeec32482c9082c9426340cee8c44dwrowe                                "113 Heuristic expiration");
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            }
10a4cdd68ef1ca0e54af296fe1d08ac00150c90bwrowe        }
6db54801798f6021bb464de7b3fdcc9dc3150f7bdgaudet        return 1;    /* Cache object is fresh (enough) */
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    }
2b484455736f4c30447aa852764f53282cbeb5ddrbb
2b484455736f4c30447aa852764f53282cbeb5ddrbb    /*
6db54801798f6021bb464de7b3fdcc9dc3150f7bdgaudet     * At this point we are stale, but: if we are under load, we may let
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * a significant number of stale requests through before the first
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * stale request successfully revalidates itself, causing a sudden
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * unexpected thundering herd which in turn brings angst and drama.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * So.
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * We want the first stale request to go through as normal. But the
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * second and subsequent request, we must pretend to be fresh until
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * the first request comes back with either new content or confirmation
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * that the stale content is still fresh.
7646be5b9ab5b098bc81d3a08a47e1931dc87597rbb     *
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * To achieve this, we create a very simple file based lock based on
10a4cdd68ef1ca0e54af296fe1d08ac00150c90bwrowe     * the key of the cached object. We attempt to open the lock file with
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * exclusive write access. If we succeed, woohoo! we're first, and we
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * follow the stale path to the backend server. If we fail, oh well,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding     * we follow the fresh path, and avoid being a thundering herd.
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb     *
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm     * The lock lives only as long as the stale request that went on ahead.
db2ef76dc744b13b9a9929ebb9e6f94712a81717rbb     * If the request succeeds, the lock is deleted. If the request fails,
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm     * the lock is deleted, and another request gets to make a new lock
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb     * and try again.
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb     *
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm     * At any time, a request marked "no-cache" will force a refresh,
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb     * ignoring the lock, ensuring an extended lockout is impossible.
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm     *
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm     * A lock that exceeds a maximum age will be deleted, and another
e4c4fcc82268e0192db234c74a6db784b879fffdrbb     * request gets to make a new lock and try again.
e4c4fcc82268e0192db234c74a6db784b879fffdrbb     */
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    status = ap_cache_try_lock(conf, r, (char *)h->cache_obj->key);
2b484455736f4c30447aa852764f53282cbeb5ddrbb    if (APR_SUCCESS == status) {
e4c4fcc82268e0192db234c74a6db784b879fffdrbb        /* we obtained a lock, follow the stale path */
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb                     "Cache lock obtained for stale cached URL, "
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                     "revalidating entry: %s",
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb                     r->unparsed_uri);
7f1290cbf118bf3d34aecc68cff2e5bd0a23e126rbb        return 0;
7f1290cbf118bf3d34aecc68cff2e5bd0a23e126rbb    }
7f1290cbf118bf3d34aecc68cff2e5bd0a23e126rbb    else if (APR_EEXIST == status) {
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        /* lock already exists, return stale data anyway, with a warning */
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
db2ef76dc744b13b9a9929ebb9e6f94712a81717rbb                     "Cache already locked for stale cached URL, "
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein                     "pretend it is fresh: %s",
cccd31fa4a72fe23cc3249c06db181b274a55a69gstein                     r->unparsed_uri);
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb
fa4e5ac791dd1c84df616b28d4ee9751efe9c64frbb        /* make sure we don't stomp on a previous warning */
fa4e5ac791dd1c84df616b28d4ee9751efe9c64frbb        warn_head = apr_table_get(h->resp_hdrs, "Warning");
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        if ((warn_head == NULL) ||
fa4e5ac791dd1c84df616b28d4ee9751efe9c64frbb            ((warn_head != NULL) && (ap_strstr_c(warn_head, "110") == NULL))) {
fa4e5ac791dd1c84df616b28d4ee9751efe9c64frbb            apr_table_merge(h->resp_hdrs, "Warning",
20c85ca0d404e29972fb94c3d6236a264d1c77abstoddard                        "110 Response is stale");
f17e3ffa43ed4f41d984925d22eb9f8139fcbf1dstoddard        }
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm
7f1290cbf118bf3d34aecc68cff2e5bd0a23e126rbb        return 1;
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    else {
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb        /* some other error occurred, just treat the object as stale */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        ap_log_error(APLOG_MARK, APLOG_DEBUG, status, r->server,
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                     "Attempt to obtain a cache lock for stale "
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                     "cached URL failed, revalidating entry anyway: %s",
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                     r->unparsed_uri);
10a4cdd68ef1ca0e54af296fe1d08ac00150c90bwrowe        return 0;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm}
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding/*
7f1290cbf118bf3d34aecc68cff2e5bd0a23e126rbb * list is a comma-separated list of case-insensitive tokens, with
d7150b84735ff36eeb3cde9c79ab2e69ee7ffd67rbb * optional whitespace around the tokens.
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm * The return returns 1 if the token val is found in the list, or 0
d7150b84735ff36eeb3cde9c79ab2e69ee7ffd67rbb * otherwise.
d7150b84735ff36eeb3cde9c79ab2e69ee7ffd67rbb */
d7150b84735ff36eeb3cde9c79ab2e69ee7ffd67rbbCACHE_DECLARE(int) ap_cache_liststr(apr_pool_t *p, const char *list,
d7150b84735ff36eeb3cde9c79ab2e69ee7ffd67rbb                                    const char *key, char **val)
d7150b84735ff36eeb3cde9c79ab2e69ee7ffd67rbb{
7f1290cbf118bf3d34aecc68cff2e5bd0a23e126rbb    apr_size_t key_len;
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    const char *next;
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (!list) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        return 0;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
e4c4fcc82268e0192db234c74a6db784b879fffdrbb    key_len = strlen(key);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    next = list;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
e4c4fcc82268e0192db234c74a6db784b879fffdrbb    for (;;) {
2b484455736f4c30447aa852764f53282cbeb5ddrbb
2b484455736f4c30447aa852764f53282cbeb5ddrbb        /* skip whitespace and commas to find the start of the next key */
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        while (*next && (apr_isspace(*next) || (*next == ','))) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            next++;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
7f1290cbf118bf3d34aecc68cff2e5bd0a23e126rbb        if (!*next) {
ffb048955d9939c0ab6ff99c2efc412d8e7a191dwrowe            return 0;
ffb048955d9939c0ab6ff99c2efc412d8e7a191dwrowe        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        if (!strncasecmp(next, key, key_len)) {
7f1290cbf118bf3d34aecc68cff2e5bd0a23e126rbb            /* this field matches the key (though it might just be
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding             * a prefix match, so make sure the match is followed
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb             * by either a space or an equals sign)
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm             */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            next += key_len;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            if (!*next || (*next == '=') || apr_isspace(*next) ||
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                (*next == ',')) {
7f1290cbf118bf3d34aecc68cff2e5bd0a23e126rbb                /* valid match */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                if (val) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                    while (*next && (*next != '=') && (*next != ',')) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                        next++;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                    if (*next == '=') {
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                        next++;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                        while (*next && apr_isspace(*next )) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                            next++;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                        }
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb                        if (!*next) {
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                            *val = NULL;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                        }
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                        else {
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                            const char *val_start = next;
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                            while (*next && !apr_isspace(*next) &&
2a7d0035b5594ddc0907a9cc545e14ae5140c541manoj                                   (*next != ',')) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                                next++;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                            }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                            *val = apr_pstrmemdup(p, val_start,
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                                                  next - val_start);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                    else {
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                        *val = NULL;
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                    }
2a7d0035b5594ddc0907a9cc545e14ae5140c541manoj                }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding                return 1;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            }
3d96ee83babeec32482c9082c9426340cee8c44dwrowe        }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        /* skip to the next field */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        do {
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm            next++;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            if (!*next) {
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                return 0;
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb            }
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        } while (*next != ',');
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding}
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding/* return each comma separated token, one at a time */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fieldingCACHE_DECLARE(const char *)ap_cache_tokstr(apr_pool_t *p, const char *list,
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm                                           const char **str)
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm{
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    apr_size_t i;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    const char *s;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    s = ap_strchr_c(list, ',');
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (s != NULL) {
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        i = s - list;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        do
b0f20a4a26bcfa85724b1c2e5ec6a077f12ef44crbb            s++;
b0f20a4a26bcfa85724b1c2e5ec6a077f12ef44crbb        while (apr_isspace(*s))
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm            ; /* noop */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
b0f20a4a26bcfa85724b1c2e5ec6a077f12ef44crbb    else
b0f20a4a26bcfa85724b1c2e5ec6a077f12ef44crbb        i = strlen(list);
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm
b0f20a4a26bcfa85724b1c2e5ec6a077f12ef44crbb    while (i > 0 && apr_isspace(list[i - 1]))
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        i--;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding
3d96ee83babeec32482c9082c9426340cee8c44dwrowe    *str = s;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    if (i)
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        return apr_pstrndup(p, list, i);
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    else
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb        return NULL;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding}
a952e0c6ece342d88f2bc04e20dcfc563398eed3rbb
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb/*
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding * Converts apr_time_t expressed as hex digits to
2b484455736f4c30447aa852764f53282cbeb5ddrbb * a true apr_time_t.
2b484455736f4c30447aa852764f53282cbeb5ddrbb */
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fieldingCACHE_DECLARE(apr_time_t) ap_cache_hex2usec(const char *x)
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding{
2cfdca5be0c69f65b43a888d6d3da846489b8fa5rbb    int i, ch;
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm    apr_time_t j;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    for (i = 0, j = 0; i < sizeof(j) * 2; i++) {
b0f20a4a26bcfa85724b1c2e5ec6a077f12ef44crbb        ch = x[i];
b0f20a4a26bcfa85724b1c2e5ec6a077f12ef44crbb        j <<= 4;
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm        if (apr_isdigit(ch))
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            j |= ch - '0';
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        else if (apr_isupper(ch))
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding            j |= ch - ('A' - 10);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding        else
b0f20a4a26bcfa85724b1c2e5ec6a077f12ef44crbb            j |= ch - ('a' - 10);
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding    }
3d96ee83babeec32482c9082c9426340cee8c44dwrowe    return j;
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding}
1ccd992d37d62c8cb2056126f2234f64ec189bfddougm
09fe0b69d3d1e8c8041c9ce99ee77b8b44b5e3b1fielding/*
b0f20a4a26bcfa85724b1c2e5ec6a077f12ef44crbb * 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);
}

/*
 * 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;
}

/*
 * Legacy call - functionally equivalent to ap_cache_cacheable_headers.
 * @deprecated @see ap_cache_cacheable_headers
 */
CACHE_DECLARE(apr_table_t *)ap_cache_cacheable_hdrs_out(apr_pool_t *p,
                                                        apr_table_t *t,
                                                        server_rec *s)
{
    return ap_cache_cacheable_headers(p,t,s);
}

/*
 * 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 = apr_table_overlay(r->pool, r->headers_out,
                                        r->err_headers_out);

    apr_table_clear(r->err_headers_out);

    headers_out = ap_cache_cacheable_headers(r->pool, headers_out,
                                                  r->server);

    if (!apr_table_get(headers_out, "Content-Type")
        && r->content_type) {
        apr_table_setn(headers_out, "Content-Type",
                       ap_make_content_type(r, r->content_type));
    }

    if (!apr_table_get(headers_out, "Content-Encoding")
        && r->content_encoding) {
        apr_table_setn(headers_out, "Content-Encoding",
                       r->content_encoding);
    }

    return headers_out;
}