Managed D-Bus 0.1: An alternative D-Bus implementation

Havoc Pennington hp at redhat.com
Wed Oct 11 07:10:14 PDT 2006


Alp Toker wrote:
> Work is currently under way to produce a full-featured managed D-Bus 
> daemon, with initial efforts directed towards completion of selinux 
> libraries necessary to support such a daemon. This is necessary to 
> support the single precision floating point primitive type available in 
> managed D-Bus, as libdbus developers have been unwilling to accommodate 
> this feature request before their 1.0 release.

To extend the type system while keeping interoperability, you would need 
to negotiate at authentication time for support of this feature. (See 
the "Invalid Protocol and Spec Extensions" section in the spec.) I would 
suggest doing this, and having the library fall back to e.g. casting the 
floats to doubles if the negotiation fails, or using a byte array, or 
whatever you think is sensible (I rarely see floats even in C, so I 
don't know what would be sensible).

To negotiate you could send a command like
"EXTENSION_DBUS_SHARP_FEATURES float whateverelse" listing features you 
support and if you get an error it's an implementation that doesn't 
understand it, and if you get a reply "EXTENSION_DBUS_SHARP_FEATURES 
float" back then the reply's listed features are the ones the other end 
understands.

Anyway, nice work on the library.

Wasn't someone working on a test suite setup to try all the bindings for 
interoperability with each other? That seems especially useful with this 
pure managed reimplementation.

Havoc



More information about the dbus mailing list