[nginx] HTTP/2: close connection on frames with self-dependency.

[Ruslan Ermilov]

details:   https://hg.nginx.org/nginx/rev/29b2dc731503
branches:  
changeset: 7564:29b2dc731503
user:      Ruslan Ermilov <ru at nginx.com>
date:      Tue Sep 10 15:33:37 2019 +0300
description:
HTTP/2: close connection on frames with self-dependency.

Don't waste server resources by sending RST_STREAM frames.  Instead,
reject HEADERS and PRIORITY frames with self-dependency by closing
connection with PROTOCOL_ERROR.

diffstat:

 src/http/v2/ngx_http_v2.c |  40 +++++++++-------------------------------
 1 files changed, 9 insertions(+), 31 deletions(-)

diffs (64 lines):

diff -r a7e8f953408e -r 29b2dc731503 src/http/v2/ngx_http_v2.c
--- a/src/http/v2/ngx_http_v2.c	Wed Sep 04 13:33:51 2019 +0300
+++ b/src/http/v2/ngx_http_v2.c	Tue Sep 10 15:33:37 2019 +0300
@@ -1107,6 +1107,14 @@ ngx_http_v2_state_headers(ngx_http_v2_co
         return ngx_http_v2_connection_error(h2c, NGX_HTTP_V2_PROTOCOL_ERROR);
     }
 
+    if (depend == h2c->state.sid) {
+        ngx_log_error(NGX_LOG_INFO, h2c->connection->log, 0,
+                      "client sent HEADERS frame for stream %ui "
+                      "with incorrect dependency", h2c->state.sid);
+
+        return ngx_http_v2_connection_error(h2c, NGX_HTTP_V2_PROTOCOL_ERROR);
+    }
+
     h2c->last_sid = h2c->state.sid;
 
     h2c->state.pool = ngx_create_pool(1024, h2c->connection->log);
@@ -1114,15 +1122,6 @@ ngx_http_v2_state_headers(ngx_http_v2_co
         return ngx_http_v2_connection_error(h2c, NGX_HTTP_V2_INTERNAL_ERROR);
     }
 
-    if (depend == h2c->state.sid) {
-        ngx_log_error(NGX_LOG_INFO, h2c->connection->log, 0,
-                      "client sent HEADERS frame for stream %ui "
-                      "with incorrect dependency", h2c->state.sid);
-
-        status = NGX_HTTP_V2_PROTOCOL_ERROR;
-        goto rst_stream;
-    }
-
     h2scf = ngx_http_get_module_srv_conf(h2c->http_connection->conf_ctx,
                                          ngx_http_v2_module);
 
@@ -1849,28 +1848,7 @@ ngx_http_v2_state_priority(ngx_http_v2_c
                       "client sent PRIORITY frame for stream %ui "
                       "with incorrect dependency", h2c->state.sid);
 
-        node = ngx_http_v2_get_node_by_id(h2c, h2c->state.sid, 0);
-
-        if (node && node->stream) {
-            if (ngx_http_v2_terminate_stream(h2c, node->stream,
-                                             NGX_HTTP_V2_PROTOCOL_ERROR)
-                == NGX_ERROR)
-            {
-                return ngx_http_v2_connection_error(h2c,
-                                                    NGX_HTTP_V2_INTERNAL_ERROR);
-            }
-
-        } else {
-            if (ngx_http_v2_send_rst_stream(h2c, h2c->state.sid,
-                                            NGX_HTTP_V2_PROTOCOL_ERROR)
-                == NGX_ERROR)
-            {
-                return ngx_http_v2_connection_error(h2c,
-                                                    NGX_HTTP_V2_INTERNAL_ERROR);
-            }
-        }
-
-        return ngx_http_v2_state_complete(h2c, pos, end);
+        return ngx_http_v2_connection_error(h2c, NGX_HTTP_V2_PROTOCOL_ERROR);
     }
 
     node = ngx_http_v2_get_node_by_id(h2c, h2c->state.sid, 1);