Hi Javier,

On Thu, Mar 1, 2012 at 1:57 PM, Javier Martinez Canillas
[off-list ref] wrote:

On 02/28/2012 08:05 PM, David Miller wrote:

quoted

From: Rodrigo Moya <redacted>
Date: Tue, 28 Feb 2012 11:47:39 +0100

quoted

Because of all of this, UDP/IP multicast wasn't even considered as an
option. We might be wrong in some/all of those, so could you please
comment on them to check if that's so?

You guys seem to want something that isn't AF_UNIX, ordering guarentees
and whatnot, it really has no place in these protocols.

You've designed a userlevel subsystem with requirements that no existing
socket layer can give, and you just figured you'd work that out later.

I think you rather should have reconsidered these premises and designed
something that could handle reality which is AF_UNIX can't do multicast
and nobody guarentees those strange ordering requirements you seem to
have.

Yes, you are right it doesn't follow AF_UNIX semantics so Unix sockets
is not the best place to add our multicast implementation.

So, now we are trying a different approach. To create a new address
family AF_MCAST. That way we can have more control over the semantics of
the socket interface for that family.

We expect to have some patches in a few days and we will resend.

Lets say AF_MCAST is acceptable, wouldn't it make AF_UNIX obsolete?

From what I can tell a lot, if not most, of users of AF_UNIX uses it

to implement some kind of IPC being it D-Bus, chromium or wayland and
eventually all of them run into the same problems. Actually the
article in lwn put it nice together: http://lwn.net/Articles/466304/

What about SCM_RIGHTS and other Ancillary Messages, would that be
acceptable in other socket families?

-- 
Luiz Augusto von Dentz