Try to correctly follow RFC 2616 13.3 on validating stale cache (945728d0) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP Apache Httpd

CHANGES

+3 −0

Original line number	Diff line number	Diff line
		Changes with Apache 2.0.53

		*) mod_cache: Try to correctly follow RFC 2616 13.3 on validating stale
		cache responses. [Justin Erenkrantz]

		*) mod_rewrite: Handle per-location rules when r->filename is unset.
		Previously this would segfault or simply not match as expected,
		depending on the platform. [Jeff Trawick]

STATUS

+1 −12

Original line number	Diff line number	Diff line
		APACHE 2.0 STATUS: --text--
		Last modified at [$Date: 2004/10/13 17:54:43 $]
		Last modified at [$Date: 2004/10/13 18:12:20 $]

		Release:

		@@ -115,17 +115,6 @@ PATCHES TO BACKPORT FROM 2.1
		jorton replies: it does indeed, hang on...
		+1: jorton

		*) Try to correctly follow RFC 2616 13.3 on validating stale cache
		responses by teaching mod_cache's cache_select_url and
		cache_save_filter how to deal with this corner case.
		modules/experimental/cache_storage.c?r1=1.39&r2=1.40
		modules/experimental/cache_util.c?r1=1.34&r2=1.35
		modules/experimental/mod_cache.c?r1=1.91&r2=1.92
		modules/experimental/mod_cache.h?r1=1.50&r2=1.51
		modules/experimental/mod_disk_cache.c?r1=1.64&r2=1.65
		modules/experimental/mod_mem_cache.c?r1=1.117&r2=1.118
		+1: stoddard, jerenkrantz, minfrin, jim

		*) mod_rewrite:Fix query string handling for proxied URLs. PR 14518.
		(2.0 + 1.3)
		modules/mappers/mod_rewrite.c: r1.259

modules/experimental/cache_storage.c

+23 −3

Original line number	Diff line number	Diff line
		@@ -245,10 +245,32 @@ int cache_select_url(request_rec r, char url)
		}
		}

		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) {
		list->provider->remove_entity(h);
		cache_info *info = &(h->cache_obj->info);

		/* Make response into a conditional */
		/* FIXME: What if the request is already conditional? */
		if (info && info->etag) {
		/* if we have a cached etag */
		cache->stale_headers = apr_table_copy(r->pool,
		r->headers_in);
		apr_table_set(r->headers_in, "If-None-Match", info->etag);
		cache->stale_handle = h;
		}
		else if (info && info->lastmods) {
		/* if we have a cached Last-Modified header */
		cache->stale_headers = apr_table_copy(r->pool,
		r->headers_in);
		apr_table_set(r->headers_in, "If-Modified-Since",
		info->lastmods);
		cache->stale_handle = h;
		}

		return DECLINED;
		}

		@@ -258,8 +280,6 @@ int cache_select_url(request_rec r, char url)
		r->filename = apr_pstrdup(r->pool, h->cache_obj->info.filename);
		accept_headers(h, r);

		cache->provider = list->provider;
		cache->provider_name = list->provider_name;
		cache->handle = h;
		return OK;
		}

modules/experimental/cache_util.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -22,12 +22,12 @@
		/* -------------------------------------------------------------- */

		/* return true if the request is conditional */
		CACHE_DECLARE(int) ap_cache_request_is_conditional(request_rec *r)
		CACHE_DECLARE(int) ap_cache_request_is_conditional(apr_table_t *table)
		{
		if (apr_table_get(r->headers_in, "If-Match") \|\|
		apr_table_get(r->headers_in, "If-None-Match") \|\|
		apr_table_get(r->headers_in, "If-Modified-Since") \|\|
		apr_table_get(r->headers_in, "If-Unmodified-Since")) {
		if (apr_table_get(table, "If-Match") \|\|
		apr_table_get(table, "If-None-Match") \|\|
		apr_table_get(table, "If-Modified-Since") \|\|
		apr_table_get(table, "If-Unmodified-Since")) {
		return 1;
		}
		return 0;

modules/experimental/mod_cache.c

+55 −23

Original line number	Diff line number	Diff line
		@@ -219,7 +219,7 @@ static int cache_out_filter(ap_filter_t f, apr_bucket_brigade bb)
		ap_log_error(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r->server,
		"cache: running CACHE_OUT filter");

		/* recall_body() was called in cache_select_url() */
		/* recall_headers() was called in cache_select_url() */
		cache->provider->recall_body(cache->handle, r->pool, bb);

		/* This filter is done once it has served up its content */
		@@ -290,6 +290,12 @@ static int cache_save_filter(ap_filter_t f, apr_bucket_brigade in)
		* This section passes the brigades into the cache modules, but only
		* if the setup section (see below) is complete.
		*/
		if (cache->block_response) {
		/* We've already sent down the response and EOS. So, ignore
		* whatever comes now.
		*/
		return APR_SUCCESS;
		}

		/* have we already run the cachability check and set up the
		* cached file handle?
		@@ -312,7 +318,6 @@ static int cache_save_filter(ap_filter_t f, apr_bucket_brigade in)
		* parameters, and decides whether this URL should be cached at
		* all. This section is* run before the above section.
		*/
		info = apr_pcalloc(r->pool, sizeof(cache_info));

		/* read expiry date; if a bad date, then leave it so the client can
		* read it
		@@ -384,7 +389,8 @@ static int cache_save_filter(ap_filter_t f, apr_bucket_brigade in)
		*/
		reason = "Query string present but no expires header";
		}
		else if (r->status == HTTP_NOT_MODIFIED && (NULL == cache->handle)) {
		else if (r->status == HTTP_NOT_MODIFIED &&
		!cache->handle && !cache->stale_handle) {
		/* if the server said 304 Not Modified but we have no cache
		* file - pass this untouched to the user agent, it's not for us.
		*/
		@@ -510,33 +516,34 @@ static int cache_save_filter(ap_filter_t f, apr_bucket_brigade in)
		* - cache->handle == NULL. In this case there is no previously
		* cached entity anywhere on the system. We must create a brand
		* new entity and store the response in it.
		* - cache->handle != NULL. In this case there is a stale
		* - cache->stale_handle != NULL. In this case there is a stale
		* entity in the system which needs to be replaced by new
		* content (unless the result was 304 Not Modified, which means
		* the cached entity is actually fresh, and we should update
		* the headers).
		*/
		/* no cache handle, create a new entity */
		if (!cache->handle) {
		rv = cache_create_entity(r, url, size);
		}
		/* pre-existing cache handle and 304, make entity fresh */
		else if (r->status == HTTP_NOT_MODIFIED) {
		/* update headers: TODO */

		/* remove this filter ??? */

		/* XXX is this right? we must set rv to something other than OK
		* in this path
		*/
		rv = HTTP_NOT_MODIFIED;
		/* Did we have a stale cache entry that really is stale? */
		if (cache->stale_handle) {
		if (r->status == HTTP_NOT_MODIFIED) {
		/* Oh, hey. It isn't that stale! Yay! */
		cache->handle = cache->stale_handle;
		info = &cache->handle->cache_obj->info;
		}
		/* pre-existing cache handle and new entity, replace entity
		* with this one
		*/
		else {
		cache->provider->remove_entity(cache->handle);
		/* Oh, well. Toss it. */
		cache->provider->remove_entity(cache->stale_handle);
		/* Treat the request as if it wasn't conditional. */
		cache->stale_handle = NULL;
		}
		}

		/* no cache handle, create a new entity */
		if (!cache->handle) {
		rv = cache_create_entity(r, url, size);
		info = apr_pcalloc(r->pool, sizeof(cache_info));
		/* We only set info->status upon the initial creation. */
		info->status = r->status;
		}

		if (rv != OK) {
		@@ -647,6 +654,31 @@ static int cache_save_filter(ap_filter_t f, apr_bucket_brigade in)
		* Write away header information to cache.
		*/
		rv = cache->provider->store_headers(cache->handle, r, info);

		/* Did we actually find an entity before, but it wasn't really stale? */
		if (rv == APR_SUCCESS && cache->stale_handle) {
		apr_bucket_brigade *bb;
		apr_bucket *bkt;

		bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);

		/* Were we initially a conditional request? */
		if (ap_cache_request_is_conditional(cache->stale_headers)) {
		/* FIXME: Should we now go and make sure it's really not
		* modified since what the user thought?
		*/
		bkt = apr_bucket_eos_create(bb->bucket_alloc);
		APR_BRIGADE_INSERT_TAIL(bb, bkt);
		}
		else {
		r->status = info->status;
		cache->provider->recall_body(cache->handle, r->pool, bb);
		}

		cache->block_response = 1;
		return ap_pass_brigade(f->next, bb);
		}

		if (rv == APR_SUCCESS) {
		rv = cache->provider->store_body(cache->handle, r, in);
		}