From: Ruediger Pluem <rpluem@apache.org>
Date: Tue, 8 Apr 2008 09:49:13 +0000 (+0000)
Subject: * In the case that we fail to read the response line from the backend and if
X-Git-Tag: 2.3.0~774
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=389a94500d7dfff5900477d26ccf7d0814e0d4b9;p=apache

* In the case that we fail to read the response line from the backend and if
  we are a reverse proxy request shutdown the connection WITHOUT ANY response
  to trigger a retry by the client if allowed (as for idempotent requests).
  BUT currently we should not do this if the request is the first request on
  a keepalive connection as browsers like seamonkey only display an empty page
  in this case and do not do a retry.

Related to PR 37770



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@645813 13f79535-47bb-0310-9956-ffa450edef68
---

diff --git a/modules/http/http_filters.c b/modules/http/http_filters.c
index 10b2ea2817..cb77bb53d4 100644
--- a/modules/http/http_filters.c
+++ b/modules/http/http_filters.c
@@ -38,6 +38,7 @@
 #include "http_main.h"
 #include "http_request.h"
 #include "http_vhost.h"
+#include "http_connection.h"
 #include "http_log.h"           /* For errors detected in basic auth common
                                  * support code... */
 #include "apr_date.h"           /* For apr_date_parse_http and APR_DATE_BAD */
@@ -1094,6 +1095,7 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_http_header_filter(ap_filter_t *f,
     header_struct h;
     header_filter_ctx *ctx = f->ctx;
     const char *ctype;
+    ap_bucket_error *eb = NULL;
 
     AP_DEBUG_ASSERT(!r->main);
 
@@ -1111,12 +1113,22 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_http_header_filter(ap_filter_t *f,
          e != APR_BRIGADE_SENTINEL(b);
          e = APR_BUCKET_NEXT(e))
     {
-        if (AP_BUCKET_IS_ERROR(e)) {
-            ap_bucket_error *eb = e->data;
-
-            ap_die(eb->status, r);
-            return AP_FILTER_ERROR;
+        if (AP_BUCKET_IS_ERROR(e) && !eb) {
+            eb = e->data;
+            continue;
         }
+        /*
+         * If we see an EOC bucket it is a signal that we should get out
+         * of the way doing nothing.
+         */
+        if (AP_BUCKET_IS_EOC(e)) {
+            ap_remove_output_filter(f);
+            return ap_pass_brigade(f->next, b);
+        }
+    }
+    if (eb) {
+        ap_die(eb->status, r);
+        return AP_FILTER_ERROR;
     }
 
     if (r->assbackwards) {
diff --git a/modules/proxy/mod_proxy_http.c b/modules/proxy/mod_proxy_http.c
index 761cdf2f2e..0d21358fdb 100644
--- a/modules/proxy/mod_proxy_http.c
+++ b/modules/proxy/mod_proxy_http.c
@@ -1359,6 +1359,38 @@ apr_status_t ap_proxy_http_process_response(apr_pool_t * p, request_rec *r,
             ap_log_rerror(APLOG_MARK, APLOG_ERR, rc, r,
                           "proxy: error reading status line from remote "
                           "server %s", backend->hostname);
+            /*
+             * If we are a reverse proxy request shutdown the connection
+             * WITHOUT ANY response to trigger a retry by the client
+             * if allowed (as for idempotent requests).
+             * BUT currently we should not do this if the request is the
+             * first request on a keepalive connection as browsers like
+             * seamonkey only display an empty page in this case and do
+             * not do a retry.
+             */
+            if (r->proxyreq == PROXYREQ_REVERSE && c->keepalives) {
+                ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
+                              "proxy: Closing connection to client because"
+                              " reading from backend server %s failed. Number"
+                              " of keepalives %i", backend->hostname, 
+                              c->keepalives);
+                ap_proxy_backend_broke(r, bb);
+                /*
+                 * Add an EOC bucket to signal the ap_http_header_filter
+                 * that it should get out of our way
+                 */
+                e = ap_bucket_eoc_create(c->bucket_alloc);
+                APR_BRIGADE_INSERT_TAIL(bb, e);
+                ap_pass_brigade(r->output_filters, bb);
+                /* Need to return OK to avoid sending an error message */
+                return OK;
+            }
+            else if (!c->keepalives) {
+                     ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
+                                   "proxy: NOT Closing connection to client"
+                                   " although reading from backend server %s"
+                                   " failed.", backend->hostname);
+            }
             return ap_proxyerror(r, HTTP_BAD_GATEWAY,
                                  "Error reading from remote server");
         }