lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Tue, 28 Feb 2012 11:47:39 +0100
From:	Rodrigo Moya <>
To:	David Miller <>
Subject: Re: [PATCH 0/10] af_unix: add multicast and filtering features to

Hi David

On Mon, 2012-02-27 at 14:05 -0500, David Miller wrote:
> From: Javier Martinez Canillas <>
> Date: Mon, 27 Feb 2012 15:00:06 +0100
> > Primary for performance reasons. D-bus is an IPC system for processes in
> > the same machine so traversing the whole TCP/IP stack seems a little
> > overkill to me.
> You haven't actually tested what the cost of this actually is, so what
> you're saying is mere speculation.  In many cases TCP/UDP over
> loopback is actually faster than AF_UNIX.
you're right we haven't tested this, but because of the other points in
Javier's mail, which are the special semantics we need for this to fit
the D-Bus usage:

> - total order is guaranteed: If sender A sends a message before B,
> receiver C and D should both get message A first and then B.
> - slow readers: dropping packets vs blocking the sender. Although
>   datagrams are not reliable on IP, datagrams on Unix sockets are
>   lost. So if one receiver has its buffer full the sender is blocked
> instead of dropping packets. That way we guarantee a reliable
> communication channel.
> - multicast group acess control: controlling who can join the
> group.
> - multicast on loopback is not supported: which means we have to use a
> NIC (i.e: eth0). 

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?


To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists