mod_cache: Implement remove URL via a filter. (ab13cb3f) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP Apache Httpd

CHANGES

+4 −0

Original line number	Diff line number	Diff line
		-- coding: utf-8 --
		Changes with Apache 2.3.0

		*) mod_cache: Remove entities from the cache when re-validation
		receives a 404 or other content-no-longer-present error.
		[Rüdiger Plüm ruediger.pluem vodafone.com]

		*) mod_disk_cache: Properly remove files from cache when needed.
		[Rüdiger Plüm ruediger.pluem vodafone.com]

modules/cache/cache_storage.c

+13 −9

Original line number	Diff line number	Diff line
		@@ -28,24 +28,28 @@ extern module AP_MODULE_DECLARE_DATA cache_module;
		* delete all URL entities from the cache
		*
		*/
		int cache_remove_url(request_rec r, char url)
		int cache_remove_url(cache_request_rec cache, apr_pool_t p)
		{
		cache_provider_list *list;
		apr_status_t rv;
		char *key;
		cache_request_rec cache = (cache_request_rec )
		ap_get_module_config(r->request_config, &cache_module);
		cache_handle_t *h;

		rv = cache_generate_key(r,r->pool,&key);
		if (rv != APR_SUCCESS) {
		return rv;
		}
		char *key;

		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;
		}

		/* for each specified cache type, delete the URL */
		while(list) {
		list->provider->remove_url(key);
		list->provider->remove_url(h, p);
		list = list->next;
		}
		return OK;

modules/cache/mod_cache.c

+82 −5

Original line number	Diff line number	Diff line
		@@ -29,6 +29,7 @@ APR_OPTIONAL_FN_TYPE(ap_cache_generate_key) *cache_generate_key;
		*/
		static ap_filter_rec_t *cache_save_filter_handle;
		static ap_filter_rec_t *cache_out_filter_handle;
		static ap_filter_rec_t *cache_remove_url_filter_handle;

		/*
		* CACHE handler
		@@ -123,6 +124,19 @@ static int cache_url_handler(request_rec *r, int lookup)
		/* add cache_save filter to cache this request */
		ap_add_output_filter_handle(cache_save_filter_handle, NULL, r,
		r->connection);

		ap_log_error(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r->server,
		"Adding CACHE_REMOVE_URL filter.");

		/* Add cache_remove_url filter to this request to remove a
		* stale cache entry if needed. Also put the current cache
		* request rec in the filter context, as the request that
		* is available later during running the filter maybe
		* different due to an internal redirect.
		*/
		cache->remove_url_filter =
		ap_add_output_filter_handle(cache_remove_url_filter_handle,
		cache, r, r->connection);
		}
		else if (cache->stale_headers) {
		ap_log_error(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r->server,
		@@ -441,11 +455,6 @@ static int cache_save_filter(ap_filter_t f, apr_bucket_brigade in)
		if (reason) {
		ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
		"cache: %s not cached. Reason: %s", url, reason);
		/* remove this object from the cache
		* BillS Asks.. Why do we need to make this call to remove_url?
		* leave it in for now..
		*/
		cache_remove_url(r, url);

		/* remove this filter from the chain */
		ap_remove_output_filter(f);
		@@ -546,6 +555,13 @@ static int cache_save_filter(ap_filter_t f, apr_bucket_brigade in)
		ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
		"cache: Caching url: %s", url);

		/* We are actually caching this response. So it does not
		* make sense to remove this entity any more.
		*/
		ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
		"cache: Removing CACHE_REMOVE_URL filter.");
		ap_remove_output_filter(cache->remove_url_filter);

		/*
		* We now want to update the cache file header information with
		* the new date, last modified, expire and content length and write
		@@ -714,6 +730,57 @@ static int cache_save_filter(ap_filter_t f, apr_bucket_brigade in)
		return ap_pass_brigade(f->next, in);
		}

		/*
		* CACHE_REMOVE_URL filter
		* ---------------
		*
		* This filter gets added in the quick handler every time the CACHE_SAVE filter
		* gets inserted. Its purpose is to remove a confirmed stale cache entry from
		* the cache.
		*
		* CACHE_REMOVE_URL has to be a protocol filter to ensure that is run even if
		* the response is a canned error message, which removes the content filters
		* and thus the CACHE_SAVE filter from the chain.
		*
		* CACHE_REMOVE_URL expects cache request rec within its context because the
		* request this filter runs on can be different from the one whose cache entry
		* should be removed, due to internal redirects.
		*
		* Note that CACHE_SAVE_URL (as a content-set filter, hence run before the
		* protocol filters) will remove this filter if it decides to cache the file.
		* Therefore, if this filter is left in, it must mean we need to toss any
		* existing files.
		*/
		static int cache_remove_url_filter(ap_filter_t f, apr_bucket_brigade in)
		{
		request_rec *r = f->r;
		cache_request_rec *cache;

		/* Setup cache_request_rec */
		cache = (cache_request_rec *) f->ctx;

		if (!cache) {
		/* user likely configured CACHE_REMOVE_URL manually; they should really
		* use mod_cache configuration to do that. So:
		* 1. Remove ourselves
		* 2. Do nothing and bail out
		*/
		ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
		"cache: CACHE_REMOVE_URL enabled unexpectedly");
		ap_remove_output_filter(f);
		return ap_pass_brigade(f->next, in);
		}
		/*
		* Now remove this cache entry from the cache
		*/
		ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
		"cache: Removing url %s from the cache", f->r->unparsed_uri);
		cache_remove_url(cache, r->pool);
		/* remove ourselves */
		ap_remove_output_filter(f);
		return ap_pass_brigade(f->next, in);
		}

		/* -------------------------------------------------------------- */
		/* Setup configurable data */

		@@ -967,6 +1034,7 @@ static int cache_post_config(apr_pool_t p, apr_pool_t plog,
		return OK;
		}


		static const command_rec cache_cmds[] =
		{
		/* XXX
		@@ -1033,6 +1101,15 @@ static void register_hooks(apr_pool_t *p)
		cache_out_filter,
		NULL,
		AP_FTYPE_CONTENT_SET+1);
		/* CACHE_REMOVE_URL has to be a protocol filter to ensure that is
		* run even if the response is a canned error message, which
		* removes the content filters.
		*/
		cache_remove_url_filter_handle =
		ap_register_output_filter("CACHE_REMOVE_URL",
		cache_remove_url_filter,
		NULL,
		AP_FTYPE_PROTOCOL);
		ap_hook_post_config(cache_post_config, NULL, NULL, APR_HOOK_REALLY_FIRST);
		}

modules/cache/mod_cache.h

+3 −2

Original line number	Diff line number	Diff line
		@@ -197,7 +197,7 @@ typedef struct {
		const char *urlkey, apr_off_t len);
		int (open_entity) (cache_handle_t h, request_rec *r,
		const char *urlkey);
		int (remove_url) (const char urlkey);
		int (remove_url) (cache_handle_t h, apr_pool_t *p);
		} cache_provider;

		/* A linked-list of authn providers. */
		@@ -225,6 +225,7 @@ typedef struct {
		apr_time_t exp; /* expiration */
		apr_time_t lastmod; /* last-modified time */
		cache_info info; / current cache info */
		ap_filter_t remove_url_filter; / Enable us to remove the filter */
		} cache_request_rec;


		@@ -271,7 +272,7 @@ CACHE_DECLARE(apr_table_t )ap_cache_cacheable_hdrs_out(apr_pool_t pool,
		/**
		* cache_storage.c
		*/
		int cache_remove_url(request_rec r, char url);
		int cache_remove_url(cache_request_rec cache, apr_pool_t p);
		int cache_create_entity(request_rec r, char url, apr_off_t size);
		int cache_select_url(request_rec r, char url);
		apr_status_t cache_generate_key_default( request_rec r, apr_pool_tp, char**key );

modules/cache/mod_mem_cache.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -601,7 +601,7 @@ static int unserialize_table( cache_header_tbl_t *ctbl,
		/* remove_url()
		* Notes:
		*/
		static int remove_url(const char *key)
		static int remove_url(cache_handle_t h, apr_pool_t p)
		{
		cache_object_t *obj;
		int cleanup = 0;
		@@ -610,7 +610,7 @@ static int remove_url(const char *key)
		apr_thread_mutex_lock(sconf->lock);
		}

		obj = cache_find(sconf->cache_cache, key);
		obj = h->cache_obj;
		if (obj) {
		cache_remove(sconf->cache_cache, obj);
		/* For performance, cleanup cache object after releasing the lock */

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