Event handling: Fix connection destroy bug

It might happen that an event is part of the epoll event queue that
belongs to a connection which was destroyed before the event is handled.
Due to this, the event handling main loop might stop and the daemon
exits. This misbehavior is fixed with this patch.

Signed-off-by: Christoph Lipka <clipka@jp.adit-jv.com>

2 files changed, 8 insertions, 0 deletions

diff --git a/src/daemon/dlt_daemon_connection.c b/src/daemon/dlt_daemon_connection.c
index 51f975d..b22f4b7 100644
--- a/src/daemon/dlt_daemon_connection.c
+++ b/src/daemon/dlt_daemon_connection.c
@@ -171,6 +171,7 @@ STATIC void dlt_connection_destroy_receiver(DltConnection *con)
     default:
         (void) dlt_receiver_free(con->receiver);
         free(con->receiver);
+        con->receiver = NULL;
         break;
     }
 }
@@ -320,6 +321,9 @@ void dlt_connection_destroy(DltConnection *to_destroy)
 {
     close(to_destroy->receiver->fd);
     dlt_connection_destroy_receiver(to_destroy);
+    /* connection pointer might be in epoll queue and used even after destroying
+     * it. To make sure it is not used anymore, connection type is invalidated */
+    to_destroy->type = DLT_CONNECTION_TYPE_MAX;
     free(to_destroy);
 }
 
diff --git a/src/daemon/dlt_daemon_event_handler.c b/src/daemon/dlt_daemon_event_handler.c
index 9ee3bc1..cfe61a4 100644
--- a/src/daemon/dlt_daemon_event_handler.c
+++ b/src/daemon/dlt_daemon_event_handler.c
@@ -137,6 +137,10 @@ int dlt_daemon_handle_event(DltEventHandler *pEvent,
             type = con->type;
             fd = con->receiver->fd;
         }
+        else /* connection might have been destroyed in the meanwhile */
+        {
+            continue;
+        }
 
         /* First of all handle epoll error events
          * We only expect EPOLLIN or EPOLLOUT