From 573ec98d2425bf5edc22d8e5e7edd17c6391d9b1 Mon Sep 17 00:00:00 2001 From: Justin Li Date: Tue, 8 Mar 2016 22:31:55 -0500 Subject: [PATCH] Upstream: avoid closing client connection in edge case. If proxy_cache is enabled, and proxy_no_cache tests true, it was previously possible for the client connection to be closed after a 304. The fix is to recheck r->header_only after the final cacheability is determined, and end the request if no longer cacheable. Example configuration: proxy_cache foo; proxy_cache_bypass 1; proxy_no_cache 1; If a client sends If-None-Match, and the upstream server returns 200 with a matching ETag, no body should be returned to the client. At the start of ngx_http_upstream_send_response proxy_no_cache is not yet tested, thus cacheable is still 1 and downstream_error is set. However, by the time the downstream_error check is done in process_request, proxy_no_cache has been tested and cacheable is set to 0. The client connection is then closed, regardless of keepalive. --- src/http/ngx_http_upstream.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c index 08fa95a93..3d01523a5 100644 --- a/src/http/ngx_http_upstream.c +++ b/src/http/ngx_http_upstream.c @@ -2861,6 +2861,11 @@ ngx_http_upstream_send_response(ngx_http_request_t *r, ngx_http_upstream_t *u) ngx_http_file_cache_free(r->cache, u->pipe->temp_file); } + if (r->header_only && !u->cacheable && !u->store) { + ngx_http_upstream_finalize_request(r, u, 0); + return; + } + #endif p = u->pipe;