Fixes skupperproject#1681: disallow link detach/reattach attempts

src/adaptors/amqp/container.c

@@ -608,7 +608,6 @@ void qd_container_handle_event(qd_container_t *container, pn_event_t *event,
         }
         break;
 
-    case PN_LINK_REMOTE_DETACH :
     case PN_LINK_REMOTE_CLOSE :
         if (!(pn_connection_state(conn) & PN_LOCAL_CLOSED)) {
             pn_link = pn_event_link(event);
@@ -642,14 +641,31 @@ void qd_container_handle_event(qd_container_t *container, pn_event_t *event,
         }
         break;
 
-    case PN_LINK_LOCAL_DETACH:
     case PN_LINK_LOCAL_CLOSE:
         pn_link = pn_event_link(event);
         if (pn_link_state(pn_link) == (PN_LOCAL_CLOSED | PN_REMOTE_CLOSED)) {
             add_link_to_free_list(&qd_conn->free_link_list, pn_link);
         }
         break;
 
+    case PN_LINK_REMOTE_DETACH:
+    case PN_LINK_LOCAL_DETACH:
+        // The router does not support detaching and reattaching links as described in the AMQP 1.0 Specification
+        // Section 2.6.4 Detaching And Reattaching A Link. If the remote attempts this it is an error - force the
+        // connection closed.
+        if (!(pn_connection_state(conn) & PN_LOCAL_CLOSED)) {
+            pn_condition_t *cond = pn_connection_condition(conn);
+            pn_condition_set_name(cond, QD_AMQP_COND_NOT_IMPLEMENTED);
+            pn_condition_set_description(cond, "Link detach/reattach not supported");
+            pn_connection_close(conn);
+
+            pn_link = pn_event_link(event);
+            qd_link = (qd_link_t*) pn_link_get_context(pn_link);
+            qd_log(LOG_CONTAINER, QD_LOG_ERROR,
+                   "[C%"PRIu64"][L%"PRIu64"] Error: Link detach/reattach not supported, connection closed",
+                   qd_conn->connection_id, qd_link ? qd_link->link_id : 0);
+        }
+        break;
 
     case PN_LINK_FLOW :
         pn_link = pn_event_link(event);

tests/system_tests_one_router.py

@@ -1083,6 +1083,16 @@ def test_50_extension_capabilities(self):
                 self.assertIn(symbol('ANONYMOUS-RELAY'), rc)
                 self.assertIn(symbol('qd.streaming-links'), rc)
 
+    def test_51_unsupported_link_reattach(self):
+        """
+        The router does not support reattaching detached links. Ensure that
+        clients attempting to detach/reattach are detected and handled as an
+        connection error
+        """
+        test = LinkReattachTest(self.address)
+        test.run()
+        self.assertIsNone(test.error)
+
 
 class Entity:
     def __init__(self, status_code, status_description, attrs):
@@ -3304,6 +3314,54 @@ def run(self):
                 sleep(0.1)
 
 
+class LinkReattachTest(MessagingHandler):
+    """
+    The router does not support link detach/re-attach. Attempt to detach a link
+    without closing it as if attempting to do a re-attach. This should cause
+    the router to force close the connection with error.
+    """
+
+    def __init__(self, addr):
+        super(LinkReattachTest, self).__init__()
+        self.address = addr
+        self.error = None
+        self.conn = None
+        self.rx_link = None
+
+    def done(self):
+        if self.timer:
+            self.timer.cancel()
+        if self.conn:
+            self.conn.close()
+
+    def timeout(self):
+        self.error = "Timeout Expired"
+        self.done()
+
+    def on_start(self, event):
+        self.timer = event.reactor.schedule(TIMEOUT, TestTimeout(self))
+        self.conn = event.container.connect(self.address)
+        self.rx_link = event.container.create_receiver(self.conn,
+                                                       source="test/reattach",
+                                                       name="ReattachTest")
+
+    def on_link_opened(self, event):
+        if event.receiver == self.rx_link:
+            # Issue a non-close detach. This is the first step in the link
+            # reattach process
+            self.rx_link.detach()
+
+    def on_connection_error(self, event):
+        # Success if the router has force-closed due to the reattach attempt
+        desc = event.connection.remote_condition.description
+        if "reattach not supported" not in desc:
+            self.error = f"Unexpected error: {desc}"
+        self.done()
+
+    def run(self):
+        Container(self).run()
+
+
 class DataConnectionCountTest(TestCase):
     """
     Start the router with different numbers of worker threads and make sure