netdev - Re: MACVLANs really best solution? How about a bridge with multiple bridge virtual interfaces?

lists.openwall.net		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 linux-hardening linux-cve-announce 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]

Message-ID: <49B53B6C.7060400@trash.net>
Date:	Mon, 09 Mar 2009 16:53:16 +0100
From:	Patrick McHardy <kaber@...sh.net>
To:	"Eric W. Biederman" <ebiederm@...ssion.com>
CC:	Mark Smith 
	<nanog@...5b20a518b8f6864949bd940457dc124746ddc.nosense.org>,
	greearb@...delatech.com, David Miller <davem@...emloft.net>,
	netdev@...r.kernel.org, shemminger@...ux-foundation.org
Subject: Re: MACVLANs really best solution? How about a bridge with multiple
 bridge virtual interfaces?

Eric W. Biederman wrote:
> There are two tricky parts.
> 
> One problem is that macvlans and the primary hardware device share the
> same transmit queue.  So when I have a broadcast packet on the primary
> devices queue I don't know if I have already sent it out to the
> macvlan devices or not.

So its about receiving packets on macvlan when transmitting on the
real device? That sounds like a really hard problem that would probably
indeed be better solved by a bridge.

If its just about whether the packet should be sent out by macvlan
to the wire as well, I'd say yes since thats what two real devices
would have done.

> The second problem is that when I transmit a multicast packet and I
> have a local listener.  I believe replicating the packet both at the
> ip layer and at the ethernet layer will result in receiving the packet
> locally twice.
> 
> I'm not certain we need to solve the second problem as having two physical
> interfaces plugged into a switch will have the same problem.

Agreed.

> The first problem is all about how do we deliver packets everywhere except self.

I think "except self should just mean "not to the originating virtual
device".
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html