* Move code for broken backend detection out of core filter into a new http

  protocol filter (ap_http_broken_backend_filter) that is only run in the
  proxy case.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@357519 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 33 insertions, 0 deletions

diff --git a/modules/http/http_core.c b/modules/http/http_core.c
index 14d8a1b598..b939967e6e 100644
--- a/modules/http/http_core.c
+++ b/modules/http/http_core.c
@@ -39,6 +39,7 @@
 AP_DECLARE_DATA ap_filter_rec_t *ap_http_input_filter_handle;
 AP_DECLARE_DATA ap_filter_rec_t *ap_http_header_filter_handle;
 AP_DECLARE_DATA ap_filter_rec_t *ap_chunk_filter_handle;
+AP_DECLARE_DATA ap_filter_rec_t *ap_broken_backend_filter_handle;
 AP_DECLARE_DATA ap_filter_rec_t *ap_byterange_filter_handle;
 
 static const char *set_keep_alive_timeout(cmd_parms *cmd, void *dummy,
@@ -242,6 +243,10 @@ static void register_hooks(apr_pool_t *p)
     ap_chunk_filter_handle =
         ap_register_output_filter("CHUNK", ap_http_chunk_filter,
                                   NULL, AP_FTYPE_TRANSCODE);
+    ap_broken_backend_filter_handle =
+        ap_register_output_filter("BROKEN_BACKEND",
+                                  ap_http_broken_backend_filter,
+                                  NULL, AP_FTYPE_PROTOCOL);
     ap_byterange_filter_handle =
         ap_register_output_filter("BYTERANGE", ap_byterange_filter,
                                   NULL, AP_FTYPE_PROTOCOL);
diff --git a/modules/http/http_filters.c b/modules/http/http_filters.c
index 750fdbda46..9434ac1668 100644
--- a/modules/http/http_filters.c
+++ b/modules/http/http_filters.c
@@ -1055,6 +1055,9 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_http_header_filter(ap_filter_t *f,
          */
         ap_add_output_filter("CHUNK", NULL, r, r->connection);
     }
+    /* If we have a Proxy request, add the BROKEN_BACKEND filter now */
+    if (r->proxyreq != PROXYREQ_NONE)
+        ap_add_output_filter("BROKEN_BACKEND", NULL, r, r->connection);
 
     /* Don't remove this filter until after we have added the CHUNK filter.
      * Otherwise, f->next won't be the CHUNK filter and thus the first
@@ -1330,3 +1333,23 @@ AP_DECLARE(long) ap_get_client_block(request_rec *r, char *buffer,
     return bufsiz;
 }
 
+apr_status_t ap_http_broken_backend_filter(ap_filter_t *f,
+                                           apr_bucket_brigade *b)
+{
+    request_rec *r = f->r;
+    apr_bucket *e;
+
+    for (e = APR_BRIGADE_FIRST(b);
+         e != APR_BRIGADE_SENTINEL(b);
+         e = APR_BUCKET_NEXT(e))
+    {
+        if (AP_BUCKET_IS_ERROR(e)
+            && (((ap_bucket_error *)(e->data))->status == HTTP_BAD_GATEWAY)) {
+            /* stream aborted and we have not ended it yet */
+            r->connection->keepalive = AP_CONN_CLOSE;
+        }
+    }
+
+    return ap_pass_brigade(f->next,  b);
+}
+
diff --git a/modules/http/mod_core.h b/modules/http/mod_core.h
index 1f5c1d8c9a..c084a755ec 100644
--- a/modules/http/mod_core.h
+++ b/modules/http/mod_core.h
@@ -42,6 +42,7 @@ extern "C" {
 extern AP_DECLARE_DATA ap_filter_rec_t *ap_http_input_filter_handle;
 extern AP_DECLARE_DATA ap_filter_rec_t *ap_http_header_filter_handle;
 extern AP_DECLARE_DATA ap_filter_rec_t *ap_chunk_filter_handle;
+extern AP_DECLARE_DATA ap_filter_rec_t *ap_broken_backend_filter_handle;
 extern AP_DECLARE_DATA ap_filter_rec_t *ap_byterange_filter_handle;
 
 /*
@@ -54,6 +55,10 @@ apr_status_t ap_http_filter(ap_filter_t *f, apr_bucket_brigade *b,
 /* HTTP/1.1 chunked transfer encoding filter. */
 apr_status_t ap_http_chunk_filter(ap_filter_t *f, apr_bucket_brigade *b);
 
+/* Filter to close the connection to the client if backend broke */
+apr_status_t ap_http_broken_backend_filter(ap_filter_t *f,
+                                           apr_bucket_brigade *b);
+
 char *ap_response_code_string(request_rec *r, int error_index);
 
 /**