msg/async: implement ECONNREFUSED detection

This commit adds code that detects ECONNREFUSED and dispatches appropriate
event further in Async messenger.

Signed-off-by: Piotr Dałek <git@predictor.org.pl>

src/msg/async/AsyncConnection.cc

@@ -99,6 +99,17 @@ class C_handle_remote_reset : public EventCallback {
   }
 };
 
+class C_handle_connection_refused : public EventCallback {
+  AsyncMessenger *msgr;
+  AsyncConnectionRef conn;
+
+ public:
+  C_handle_connection_refused(AsyncMessenger *m, AsyncConnectionRef c): msgr(m), conn(c) {}
+  void do_request(int id) {
+    msgr->ms_deliver_handle_refused(conn.get());
+  }
+};
+
 class C_handle_dispatch : public EventCallback {
   AsyncMessenger *msgr;
   Message *m;
@@ -189,6 +200,7 @@ AsyncConnection::AsyncConnection(CephContext *cct, AsyncMessenger *m, EventCente
   reset_handler = new C_handle_reset(async_msgr, this);
   remote_reset_handler = new C_handle_remote_reset(async_msgr, this);
   connect_handler = new C_deliver_connect(async_msgr, this);
+  connection_refused_handler = new C_handle_connection_refused(async_msgr, this);
   local_deliver_handler = new C_local_deliver(this);
   wakeup_handler = new C_time_wakeup(this);
   memset(msgvec, 0, sizeof(msgvec));
@@ -1074,6 +1086,10 @@ ssize_t AsyncConnection::_process_connection()
         r = net.reconnect(get_peer_addr(), sd);
         if (r < 0) {
           ldout(async_msgr->cct, 1) << __func__ << " reconnect failed " << dendl;
+          if (r == -ECONNREFUSED) {
+            ldout(async_msgr->cct, 2) << __func__ << " connection refused!" << dendl;
+            center->dispatch_event_external(connection_refused_handler);
+          }
           goto fail;
         } else if (r > 0) {
           break;

src/msg/async/AsyncConnection.h

@@ -306,6 +306,7 @@ class AsyncConnection : public Connection {
   EventCallbackRef write_handler;
   EventCallbackRef reset_handler;
   EventCallbackRef remote_reset_handler;
+  EventCallbackRef connection_refused_handler;
   EventCallbackRef connect_handler;
   EventCallbackRef local_deliver_handler;
   EventCallbackRef wakeup_handler;
@@ -375,6 +376,7 @@ class AsyncConnection : public Connection {
     delete write_handler;
     delete reset_handler;
     delete remote_reset_handler;
+    delete connection_refused_handler;
     delete connect_handler;
     delete local_deliver_handler;
     delete wakeup_handler;