/* 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. */ #define CORE_PRIVATE #include "mod_cache.h" extern APR_OPTIONAL_FN_TYPE(ap_cache_generate_key) *cache_generate_key; extern module AP_MODULE_DECLARE_DATA cache_module; /* -------------------------------------------------------------- */ /* * delete all URL entities from the cache * */ int cache_remove_url(cache_request_rec *cache, apr_pool_t *p) { cache_provider_list *list; cache_handle_t *h; list = cache->providers; /* Remove the stale cache entry if present. If not, we're * being called from outside of a request; remove the * non-stalle handle. */ h = cache->stale_handle ? cache->stale_handle : cache->handle; if (!h) { return OK; } ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, NULL, "cache: Removing url %s from the cache", h->cache_obj->key); /* for each specified cache type, delete the URL */ while(list) { list->provider->remove_url(h, p); list = list->next; } return OK; } /* * create a new URL entity in the cache * * It is possible to store more than once entity per URL. This * function will always create a new entity, regardless of whether * other entities already exist for the same URL. * * The size of the entity is provided so that a cache module can * decide whether or not it wants to cache this particular entity. * If the size is unknown, a size of -1 should be set. */ int cache_create_entity(request_rec *r, apr_off_t size) { cache_provider_list *list; cache_handle_t *h = apr_pcalloc(r->pool, sizeof(cache_handle_t)); char *key; apr_status_t rv; cache_request_rec *cache = (cache_request_rec *) ap_get_module_config(r->request_config, &cache_module); rv = cache_generate_key(r, r->pool, &key); if (rv != APR_SUCCESS) { return rv; } list = cache->providers; /* for each specified cache type, delete the URL */ while (list) { switch (rv = list->provider->create_entity(h, r, key, size)) { case OK: { cache->handle = h; cache->provider = list->provider; cache->provider_name = list->provider_name; return OK; } case DECLINED: { list = list->next; continue; } default: { return rv; } } } return DECLINED; } static int set_cookie_doo_doo(void *v, const char *key, const char *val) { apr_table_addn(v, key, val); return 1; } CACHE_DECLARE(void) ap_cache_accept_headers(cache_handle_t *h, request_rec *r, int preserve_orig) { apr_table_t *cookie_table, *hdr_copy; const char *v; v = apr_table_get(h->resp_hdrs, "Content-Type"); if (v) { ap_set_content_type(r, v); apr_table_unset(h->resp_hdrs, "Content-Type"); /* * Also unset possible Content-Type headers in r->headers_out and * r->err_headers_out as they may be different to what we have received * from the cache. * Actually they are not needed as r->content_type set by * ap_set_content_type above will be used in the store_headers functions * of the storage providers as a fallback and the HTTP_HEADER filter * does overwrite the Content-Type header with r->content_type anyway. */ apr_table_unset(r->headers_out, "Content-Type"); apr_table_unset(r->err_headers_out, "Content-Type"); } /* If the cache gave us a Last-Modified header, we can't just * pass it on blindly because of restrictions on future values. */ v = apr_table_get(h->resp_hdrs, "Last-Modified"); if (v) { ap_update_mtime(r, apr_date_parse_http(v)); ap_set_last_modified(r); apr_table_unset(h->resp_hdrs, "Last-Modified"); } /* The HTTP specification says that it is legal to merge duplicate * headers into one. Some browsers that support Cookies don't like * merged headers and prefer that each Set-Cookie header is sent * separately. Lets humour those browsers by not merging. * Oh what a pain it is. */ cookie_table = apr_table_make(r->pool, 2); apr_table_do(set_cookie_doo_doo, cookie_table, r->err_headers_out, "Set-Cookie", NULL); apr_table_do(set_cookie_doo_doo, cookie_table, h->resp_hdrs, "Set-Cookie", NULL); apr_table_unset(r->err_headers_out, "Set-Cookie"); apr_table_unset(h->resp_hdrs, "Set-Cookie"); if (preserve_orig) { hdr_copy = apr_table_copy(r->pool, h->resp_hdrs); apr_table_overlap(hdr_copy, r->headers_out, APR_OVERLAP_TABLES_SET); r->headers_out = hdr_copy; } else { apr_table_overlap(r->headers_out, h->resp_hdrs, APR_OVERLAP_TABLES_SET); } if (!apr_is_empty_table(cookie_table)) { r->err_headers_out = apr_table_overlay(r->pool, r->err_headers_out, cookie_table); } } /* * select a specific URL entity in the cache * * It is possible to store more than one entity per URL. Content * negotiation is used to select an entity. Once an entity is * selected, details of it are stored in the per request * config to save time when serving the request later. * * This function returns OK if successful, DECLINED if no * cached entity fits the bill. */ int cache_select(request_rec *r) { cache_provider_list *list; apr_status_t rv; cache_handle_t *h; char *key; cache_request_rec *cache = (cache_request_rec *) ap_get_module_config(r->request_config, &cache_module); rv = cache_generate_key(r, r->pool, &key); if (rv != APR_SUCCESS) { return rv; } /* go through the cache types till we get a match */ h = apr_palloc(r->pool, sizeof(cache_handle_t)); list = cache->providers; while (list) { switch ((rv = list->provider->open_entity(h, r, key))) { case OK: { char *vary = NULL; int fresh; if (list->provider->recall_headers(h, r) != APR_SUCCESS) { /* TODO: Handle this error */ return DECLINED; } /* * Check Content-Negotiation - Vary * * At this point we need to make sure that the object we found in * the cache is the same object that would be delivered to the * client, when the effects of content negotiation are taken into * effect. * * In plain english, we want to make sure that a language-negotiated * document in one language is not given to a client asking for a * language negotiated document in a different language by mistake. * * This code makes the assumption that the storage manager will * cache the req_hdrs if the response contains a Vary * header. * * RFC2616 13.6 and 14.44 describe the Vary mechanism. */ vary = apr_pstrdup(r->pool, apr_table_get(h->resp_hdrs, "Vary")); while (vary && *vary) { char *name = vary; const char *h1, *h2; /* isolate header name */ while (*vary && !apr_isspace(*vary) && (*vary != ',')) ++vary; while (*vary && (apr_isspace(*vary) || (*vary == ','))) { *vary = '\0'; ++vary; } /* * is this header in the request and the header in the cached * request identical? If not, we give up and do a straight get */ h1 = apr_table_get(r->headers_in, name); h2 = apr_table_get(h->req_hdrs, name); if (h1 == h2) { /* both headers NULL, so a match - do nothing */ } else if (h1 && h2 && !strcmp(h1, h2)) { /* both headers exist and are equal - do nothing */ } else { /* headers do not match, so Vary failed */ ap_log_error(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r->server, "cache_select_url(): Vary header mismatch."); return DECLINED; } } cache->provider = list->provider; cache->provider_name = list->provider_name; /* Is our cached response fresh enough? */ fresh = ap_cache_check_freshness(h, r); if (!fresh) { const char *etag, *lastmod; ap_log_error(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r->server, "Cached response for %s isn't fresh. Adding/replacing " "conditional request headers.", r->uri); /* Make response into a conditional */ cache->stale_headers = apr_table_copy(r->pool, r->headers_in); /* We can only revalidate with our own conditionals: remove the * conditions from the original request. */ apr_table_unset(r->headers_in, "If-Match"); apr_table_unset(r->headers_in, "If-Modified-Since"); apr_table_unset(r->headers_in, "If-None-Match"); apr_table_unset(r->headers_in, "If-Range"); apr_table_unset(r->headers_in, "If-Unmodified-Since"); /* * Do not do Range requests with our own conditionals: If * we get 304 the Range does not matter and otherwise the * entity changed and we want to have the complete entity */ apr_table_unset(r->headers_in, "Range"); etag = apr_table_get(h->resp_hdrs, "ETag"); lastmod = apr_table_get(h->resp_hdrs, "Last-Modified"); if (etag || lastmod) { /* If we have a cached etag and/or Last-Modified add in * our own conditionals. */ if (etag) { apr_table_set(r->headers_in, "If-None-Match", etag); } if (lastmod) { apr_table_set(r->headers_in, "If-Modified-Since", lastmod); } cache->stale_handle = h; } else { int irv; /* * The copy isn't fresh enough, but we cannot revalidate. * So it is the same case as if there had not been a cached * entry at all. Thus delete the entry from cache. */ irv = cache->provider->remove_url(h, r->pool); if (irv != OK) { ap_log_error(APLOG_MARK, APLOG_DEBUG, irv, r->server, "cache: attempt to remove url from cache unsuccessful."); } } return DECLINED; } /* Okay, this response looks okay. Merge in our stuff and go. */ ap_cache_accept_headers(h, r, 0); cache->handle = h; return OK; } case DECLINED: { /* try again with next cache type */ list = list->next; continue; } default: { /* oo-er! an error */ return rv; } } } return DECLINED; } apr_status_t cache_generate_key_default(request_rec *r, apr_pool_t* p, char**key) { cache_server_conf *conf; cache_request_rec *cache; char *port_str, *hn, *lcs; const char *hostname, *scheme; int i; cache = (cache_request_rec *) ap_get_module_config(r->request_config, &cache_module); if (!cache) { /* This should never happen */ ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server, "cache: No cache request information available for key" " generation"); *key = ""; return APR_EGENERAL; } if (cache->key) { /* * We have been here before during the processing of this request. * So return the key we already have. */ *key = apr_pstrdup(p, cache->key); return APR_SUCCESS; } /* * Get the module configuration. We need this for the CacheIgnoreQueryString * option below. */ conf = (cache_server_conf *) ap_get_module_config(r->server->module_config, &cache_module); /* * Use the canonical name to improve cache hit rate, but only if this is * not a proxy request or if this is a reverse proxy request. * We need to handle both cases in the same manner as for the reverse proxy * case we have the following situation: * * If a cached entry is looked up by mod_cache's quick handler r->proxyreq * is still unset in the reverse proxy case as it only gets set in the * translate name hook (either by ProxyPass or mod_rewrite) which is run * after the quick handler hook. This is different to the forward proxy * case where it gets set before the quick handler is run (in the * post_read_request hook). * If a cache entry is created by the CACHE_SAVE filter we always have * r->proxyreq set correctly. * So we must ensure that in the reverse proxy case we use the same code * path and using the canonical name seems to be the right thing to do * in the reverse proxy case. */ if (!r->proxyreq || (r->proxyreq == PROXYREQ_REVERSE)) { /* Use _default_ as the hostname if none present, as in mod_vhost */ hostname = ap_get_server_name(r); if (!hostname) { hostname = "_default_"; } } else if(r->parsed_uri.hostname) { /* Copy the parsed uri hostname */ hn = apr_pstrdup(p, r->parsed_uri.hostname); ap_str_tolower(hn); /* const work-around */ hostname = hn; } else { /* We are a proxied request, with no hostname. Unlikely * to get very far - but just in case */ hostname = "_default_"; } /* * Copy the scheme, ensuring that it is lower case. If the parsed uri * contains no string or if this is not a proxy request get the http * scheme for this request. As r->parsed_uri.scheme is not set if this * is a reverse proxy request, it is ensured that the cases * "no proxy request" and "reverse proxy request" are handled in the same * manner (see above why this is needed). */ if (r->proxyreq && r->parsed_uri.scheme) { /* Copy the scheme and lower-case it */ lcs = apr_pstrdup(p, r->parsed_uri.scheme); ap_str_tolower(lcs); /* const work-around */ scheme = lcs; } else { scheme = ap_http_scheme(r); } /* * If this is a proxy request, but not a reverse proxy request (see comment * above why these cases must be handled in the same manner), copy the * URI's port-string (which may be a service name). If the URI contains * no port-string, use apr-util's notion of the default port for that * scheme - if available. Otherwise use the port-number of the current * server. */ if(r->proxyreq && (r->proxyreq != PROXYREQ_REVERSE)) { if (r->parsed_uri.port_str) { port_str = apr_pcalloc(p, strlen(r->parsed_uri.port_str) + 2); port_str[0] = ':'; for (i = 0; r->parsed_uri.port_str[i]; i++) { port_str[i + 1] = apr_tolower(r->parsed_uri.port_str[i]); } } else if (apr_uri_port_of_scheme(scheme)) { port_str = apr_psprintf(p, ":%u", apr_uri_port_of_scheme(scheme)); } else { /* No port string given in the AbsoluteUri, and we have no * idea what the default port for the scheme is. Leave it * blank and live with the inefficiency of some extra cached * entities. */ port_str = ""; } } else { /* Use the server port */ port_str = apr_psprintf(p, ":%u", ap_get_server_port(r)); } /* Key format is a URI, optionally without the query-string */ if (conf->ignorequerystring) { *key = apr_pstrcat(p, scheme, "://", hostname, port_str, r->parsed_uri.path, "?", NULL); } else { *key = apr_pstrcat(p, scheme, "://", hostname, port_str, r->parsed_uri.path, "?", r->parsed_uri.query, NULL); } /* * Store the key in the request_config for the cache as r->parsed_uri * might have changed in the time from our first visit here triggered by the * quick handler and our possible second visit triggered by the CACHE_SAVE * filter (e.g. r->parsed_uri got unescaped). In this case we would save the * resource in the cache under a key where it is never found by the quick * handler during following requests. */ cache->key = apr_pstrdup(r->pool, *key); return APR_SUCCESS; }
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