Fixed WebSocket connection hang issue after listener reconfigure.

Because the configuration values were read from the listener's configuration,
an established WebSocket connection was unable to work properly (i. e. stuck)
if the listener was removed.  The correct source of configuration values is the
request config joint.

This is related to issue #581 on GitHub.

3 files changed, 39 insertions, 29 deletions

diff --git a/docs/changes.xml b/docs/changes.xml
index 4519f6e9..5855466e 100644
--- a/docs/changes.xml
+++ b/docs/changes.xml
@@ -37,6 +37,13 @@ fixed building with glibc 2.34, notably Fedora 35.
 </para>
 </change>
 
+<change type="bugfix">
+<para>
+established WebSocket connections could stop reading frames from the client
+after the corresponding listener had been reconfigured.
+</para>
+</change>
+
 </changes>
 
 
diff --git a/src/nxt_h1proto_websocket.c b/src/nxt_h1proto_websocket.c
index 42a50a34..7be190f6 100644
--- a/src/nxt_h1proto_websocket.c
+++ b/src/nxt_h1proto_websocket.c
@@ -73,10 +73,10 @@ void
 nxt_h1p_websocket_first_frame_start(nxt_task_t *task, nxt_http_request_t *r,
     nxt_buf_t *ws_frame)
 {
-    nxt_conn_t               *c;
-    nxt_timer_t              *timer;
-    nxt_h1proto_t            *h1p;
-    nxt_socket_conf_joint_t  *joint;
+    nxt_conn_t            *c;
+    nxt_timer_t           *timer;
+    nxt_h1proto_t         *h1p;
+    nxt_websocket_conf_t  *websocket_conf;
 
     nxt_debug(task, "h1p ws first frame start");
 
@@ -87,11 +87,9 @@ nxt_h1p_websocket_first_frame_start(nxt_task_t *task, nxt_http_request_t *r,
         nxt_conn_tcp_nodelay_on(task, c);
     }
 
-    joint = c->listen->socket.data;
+    websocket_conf = &r->conf->socket_conf->websocket_conf;
 
-    if (nxt_slow_path(joint != NULL
-        && joint->socket_conf->websocket_conf.keepalive_interval != 0))
-    {
+    if (nxt_slow_path(websocket_conf->keepalive_interval != 0)) {
         h1p->websocket_timer = nxt_mp_zget(c->mem_pool,
                                            sizeof(nxt_h1p_websocket_timer_t));
         if (nxt_slow_path(h1p->websocket_timer == NULL)) {
@@ -100,7 +98,7 @@ nxt_h1p_websocket_first_frame_start(nxt_task_t *task, nxt_http_request_t *r,
         }
 
         h1p->websocket_timer->keepalive_interval =
-            joint->socket_conf->websocket_conf.keepalive_interval;
+            websocket_conf->keepalive_interval;
         h1p->websocket_timer->h1p = h1p;
 
         timer = &h1p->websocket_timer->timer;
@@ -218,14 +216,13 @@ static const nxt_conn_state_t  nxt_h1p_read_ws_frame_header_state
 static void
 nxt_h1p_conn_ws_frame_header_read(nxt_task_t *task, void *obj, void *data)
 {
-    size_t                   size, hsize, frame_size, max_frame_size;
-    uint64_t                 payload_len;
-    nxt_conn_t               *c;
-    nxt_h1proto_t            *h1p;
-    nxt_http_request_t       *r;
-    nxt_event_engine_t       *engine;
-    nxt_websocket_header_t   *wsh;
-    nxt_socket_conf_joint_t  *joint;
+    size_t                  size, hsize, frame_size, max_frame_size;
+    uint64_t                payload_len;
+    nxt_conn_t              *c;
+    nxt_h1proto_t           *h1p;
+    nxt_http_request_t      *r;
+    nxt_event_engine_t      *engine;
+    nxt_websocket_header_t  *wsh;
 
     c = obj;
     h1p = data;
@@ -265,17 +262,6 @@ nxt_h1p_conn_ws_frame_header_read(nxt_task_t *task, void *obj, void *data)
 
     r->ws_frame = c->read;
 
-    joint = c->listen->socket.data;
-
-    if (nxt_slow_path(joint == NULL)) {
-        /*
-         * Listening socket had been closed while
-         * connection was in keep-alive state.
-         */
-        c->read_state = &nxt_h1p_idle_close_state;
-        return;
-    }
-
     if (nxt_slow_path(wsh->mask == 0)) {
         hxt_h1p_send_ws_error(task, r, &nxt_ws_err_not_masked);
         return;
@@ -330,7 +316,7 @@ nxt_h1p_conn_ws_frame_header_read(nxt_task_t *task, void *obj, void *data)
         h1p->websocket_cont_expected = !wsh->fin;
     }
 
-    max_frame_size = joint->socket_conf->websocket_conf.max_frame_size;
+    max_frame_size = r->conf->socket_conf->websocket_conf.max_frame_size;
 
     payload_len = nxt_websocket_frame_payload_len(wsh);
 
diff --git a/test/test_asgi_websockets.py b/test/test_asgi_websockets.py
index 140bcb9a..7da2d9ce 100644
--- a/test/test_asgi_websockets.py
+++ b/test/test_asgi_websockets.py
@@ -1481,3 +1481,20 @@ class TestASGIWebsockets(TestApplicationPython):
         self.check_frame(frame, True, self.ws.OP_PING, '')  # PING frame
 
         sock.close()
+
+    def test_asgi_websockets_client_locks_app(self):
+        self.load('websockets/mirror')
+
+        message = 'blah'
+
+        _, sock, _ = self.ws.upgrade()
+
+        assert 'success' in self.conf({}), 'remove app'
+
+        self.ws.frame_write(sock, self.ws.OP_TEXT, message)
+
+        frame = self.ws.frame_read(sock)
+
+        assert message == frame['data'].decode('utf-8'), 'client'
+
+        sock.close()