help interpreting dbus failure messages - "Rejected send message"

[Simon McVittie]

On 01/04/13 07:31, John wrote:
> member="GetAll" error name="(unset)" requested_reply="0"
...
> Is the 'name="(unset)"' normal?  If not, what would cause that?

It's 'error name="(unset)"', and, yes, it is normal for messages with
type="method_call" not to have an error name. Only messages with
type="error" have an error name. When it complains about a rejected
message, the dbus-daemon outputs the same information for all messages,
rather than looking at the message type and only outputting the fields
that would make sense for that message type.

The situation here is that gnome-control-center (run by the user with
uid 1000) has tried sending the org.freedesktop.DBus.Properties.GetAll()
method call to NetworkManager, but the system bus' message policy does
not allow it to do so, so dbus-daemon logs a warning to the syslog and
sends back an error reply to gnome-control-center.

On my system (which isn't running current GNOME), NetworkManager's
policy file in /etc/dbus-1/system.d allows various method calls for
unprivileged users, but not org.freedesktop.DBus.Properties.GetAll(). If
NM actively uses Properties then its policy file will need to allow
that; or if it doesn't use Properties, the bug might be that an author
of gnome-control-center (or a library it uses) forgot to specify
G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES.

    S