Process early errors via a dummy HTTP/1.1 request as well

Process early errors via a dummy HTTP/1.1 request as well to ensure
that the request gets logged correctly and possible custom error
pages are considered. The previous way of directly sending a HTTP/2
answer with the HTTP status code appropriate for the error is more
efficient, but does not log the request nor sents a possible custom
error page.

* modules/http2/h2.h: Add http_status to h2_request struct and define
  H2_HTTP_STATUS_UNSET.

* modules/http2/h2_request.c(h2_request_create_rec): Check if
  http_status is set for the request and die with the
  status code it contains if set.

* modules/http2/h2_session.c(on_header_cb): Adjust the error condition
  now that we mark early errors via http_status: Only return an error
  if the status is not success and http_status is not H2_HTTP_STATUS_UNSET.

* modules/http2/h2_stream.c(set_error_response): Set http_status
  on the request instead of creating headers for a response and a
  respective brigade.

Github: closes #137


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1881620 13f79535-47bb-0310-9956-ffa450edef68

modules/http2/h2.h

@@ -141,8 +141,19 @@ struct h2_request {
     unsigned int chunked : 1;   /* iff request body needs to be forwarded as chunked */
     unsigned int serialize : 1; /* iff this request is written in HTTP/1.1 serialization */
     apr_off_t raw_bytes;        /* RAW network bytes that generated this request - if known. */
+    int http_status;            /* Store a possible HTTP status code that gets
+                                 * defined before creating the dummy HTTP/1.1
+                                 * request e.g. due to an error already
+                                 * detected.
+                                 */
 };
 
+/*
+ * A possible HTTP status code is not defined yet. See the http_status field
+ * in struct h2_request above for further explanation.
+ */
+#define H2_HTTP_STATUS_UNSET (0)
+
 typedef struct h2_headers h2_headers;
 
 struct h2_headers {

modules/http2/h2_request.c

@@ -84,6 +84,7 @@ apr_status_t h2_request_rcreate(h2_request **preq, apr_pool_t *pool,
     req->authority   = authority;
     req->path        = path;
     req->headers     = apr_table_make(pool, 10);
+    req->http_status = H2_HTTP_STATUS_UNSET;
     if (r->server) {
         req->serialize = h2_config_rgeti(r, H2_CONF_SER_HEADERS);
     }
@@ -294,7 +295,14 @@ request_rec *h2_request_create_rec(const h2_request *req, conn_rec *c)
     if (!ap_parse_request_line(r) || !ap_check_request_header(r)) {
         /* we may have switched to another server still */
         r->per_dir_config = r->server->lookup_defaults;
+        if (req->http_status != H2_HTTP_STATUS_UNSET) {
+            access_status = req->http_status;
+            /* Be safe and close the connection */
+            c->keepalive = AP_CONN_CLOSE;
+        }
+        else {
             access_status = r->status;
+        }
         r->status = HTTP_OK;
         goto die;
     }
@@ -302,6 +310,14 @@ request_rec *h2_request_create_rec(const h2_request *req, conn_rec *c)
     /* we may have switched to another server */
     r->per_dir_config = r->server->lookup_defaults;
 
+    if (req->http_status != H2_HTTP_STATUS_UNSET) {
+        access_status = req->http_status;
+        r->status = HTTP_OK;
+        /* Be safe and close the connection */
+        c->keepalive = AP_CONN_CLOSE;
+        goto die;
+    }
+
     /*
      * Add the HTTP_IN filter here to ensure that ap_discard_request_body
      * called by ap_die and by ap_send_error_response works correctly on

modules/http2/h2_session.c

@@ -311,7 +311,9 @@ static int on_header_cb(nghttp2_session *ngh2, const nghttp2_frame *frame,
     
     status = h2_stream_add_header(stream, (const char *)name, namelen,
                                   (const char *)value, valuelen);
-    if (status != APR_SUCCESS && !h2_stream_is_ready(stream)) {
+    if (status != APR_SUCCESS
+        && (!stream->rtmp
+            || stream->rtmp->http_status == H2_HTTP_STATUS_UNSET)) {
         return NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE;
     }
     return 0;

modules/http2/h2_stream.c

@@ -639,16 +639,7 @@ void h2_stream_set_request(h2_stream *stream, const h2_request *r)
 static void set_error_response(h2_stream *stream, int http_status)
 {
     if (!h2_stream_is_ready(stream)) {
-        conn_rec *c = stream->session->c;
-        apr_bucket *b;
-        h2_headers *response;
-        
-        response = h2_headers_die(http_status, stream->request, stream->pool);
-        prep_output(stream);
-        b = apr_bucket_eos_create(c->bucket_alloc);
-        APR_BRIGADE_INSERT_HEAD(stream->out_buffer, b);
-        b = h2_bucket_headers_create(c->bucket_alloc, response);
-        APR_BRIGADE_INSERT_HEAD(stream->out_buffer, b);
+        stream->rtmp->http_status = http_status;
     }
 }