# HG changeset patch
# User Roman Arutyunyan <arut@nginx.com>
# Date 1627542216 -10800
# Node ID d80365ca678d9d09aaec94341702903e879cdeb3
# Parent  4009f120cad4c608b132023288d815e68e2bef46
HTTP/3: require mandatory uni streams before additional ones.

As per quic-http-34:

   Endpoints SHOULD create the HTTP control stream as well as the
   unidirectional streams required by mandatory extensions (such as the
   QPACK encoder and decoder streams) first, and then create additional
   streams as allowed by their peer.

Previously, client could create and destroy additional uni streams unlimited
number of times before creating mandatory streams.

diff --git a/src/http/v3/ngx_http_v3_streams.c b/src/http/v3/ngx_http_v3_streams.c
--- a/src/http/v3/ngx_http_v3_streams.c
+++ b/src/http/v3/ngx_http_v3_streams.c
@@ -91,6 +91,8 @@ ngx_http_v3_register_uni_stream(ngx_conn
     ngx_http_v3_session_t     *h3c;
     ngx_http_v3_uni_stream_t  *us;
 
+    h3c = ngx_http_v3_get_session(c);
+
     switch (type) {
 
     case NGX_HTTP_V3_STREAM_ENCODER:
@@ -119,12 +121,19 @@ ngx_http_v3_register_uni_stream(ngx_conn
 
         ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                        "http3 stream 0x%02xL", type);
+
+        if (h3c->known_streams[NGX_HTTP_V3_STREAM_CLIENT_ENCODER] == NULL
+            || h3c->known_streams[NGX_HTTP_V3_STREAM_CLIENT_DECODER] == NULL
+            || h3c->known_streams[NGX_HTTP_V3_STREAM_CLIENT_CONTROL] == NULL)
+        {
+            ngx_log_error(NGX_LOG_INFO, c->log, 0, "missing mandatory stream");
+            return NGX_HTTP_V3_ERR_STREAM_CREATION_ERROR;
+        }
+
         index = -1;
     }
 
     if (index >= 0) {
-        h3c = ngx_http_v3_get_session(c);
-
         if (h3c->known_streams[index]) {
             ngx_log_error(NGX_LOG_INFO, c->log, 0, "stream exists");
             return NGX_HTTP_V3_ERR_STREAM_CREATION_ERROR;