Log to syslog when auth_timeout drops an incomplete connection

This is a symptom of either a denial of service attack, or a
serious performance problem. Either way, sysadmins should know.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=86431

diff --git a/bus/connection.c b/bus/connection.c
index 519122c..7107434 100644 (file)
--- a/bus/connection.c
+++ b/bus/connection.c
@@ -860,6 +860,14 @@ bus_connections_expire_incomplete (BusConnections *connections)
 
           if (elapsed >= (double) auth_timeout)
             {
+              /* Unfortunately, we can't identify the connection: it doesn't
+               * have a unique name yet, we don't know its uid/pid yet,
+               * and so on. */
+              bus_context_log (connections->context, DBUS_SYSTEM_LOG_INFO,
+                  "Connection has not authenticated soon enough, closing it "
+                  "(auth_timeout=%dms, elapsed: %.0fms)",
+                  auth_timeout, elapsed);
+
               _dbus_verbose ("Timing out authentication for connection %p\n", connection);
               dbus_connection_close (connection);
             }