From: Roman Arutyunyan <arut@nginx.com>
Date: Thu, 29 Jul 2021 13:01:37 +0000 (+0300)
Subject: HTTP/3: close connection on keepalive_requests * 2.
X-Git-Url: http://git.kaiwu.me/postgresql/log/contrib/postgres_fdw/postgres_fdw.c?a=commitdiff_plain;h=e1ad576f960ab2b455b4d12869f69cb648feba42;p=nginx.git

HTTP/3: close connection on keepalive_requests * 2.

After receiving GOAWAY, client is not supposed to create new streams.  However,
until client reads this frame, we allow it to create new streams, which are
gracefully rejected.  To prevent client from abusing this algorithm, a new
limit is introduced.  Upon reaching keepalive_requests * 2, server now closes
the entire QUIC connection claiming excessive load.
---

diff --git a/src/http/v3/ngx_http_v3_request.c b/src/http/v3/ngx_http_v3_request.c
index 5fc6e233b..f45a7b95e 100644
--- a/src/http/v3/ngx_http_v3_request.c
+++ b/src/http/v3/ngx_http_v3_request.c
@@ -81,6 +81,15 @@ ngx_http_v3_init(ngx_connection_t *c)
 
     clcf = ngx_http_get_module_loc_conf(hc->conf_ctx, ngx_http_core_module);
 
+    n = c->quic->id >> 2;
+
+    if (n >= clcf->keepalive_requests * 2) {
+        ngx_http_v3_finalize_connection(c, NGX_HTTP_V3_ERR_EXCESSIVE_LOAD,
+                                        "too many requests per connection");
+        ngx_http_close_connection(c);
+        return;
+    }
+
     h3c = ngx_http_v3_get_session(c);
 
     if (h3c->goaway) {
@@ -89,8 +98,6 @@ ngx_http_v3_init(ngx_connection_t *c)
         return;
     }
 
-    n = c->quic->id >> 2;
-
     if (n + 1 == clcf->keepalive_requests
         || ngx_current_msec - c->quic->parent->start_time
            > clcf->keepalive_time)