Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753641Ab0DMUsZ (ORCPT ); Tue, 13 Apr 2010 16:48:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52228 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752793Ab0DMUsY (ORCPT ); Tue, 13 Apr 2010 16:48:24 -0400 Date: Tue, 13 Apr 2010 23:43:07 +0300 From: "Michael S. Tsirkin" To: Eric Dumazet Cc: Jan Kiszka , "David S. Miller" , Herbert Xu , Paul Moore , David Woodhouse , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , qemu-devel Subject: Re: [PATCH] tun: orphan an skb on tx Message-ID: <20100413204307.GC3582@redhat.com> References: <20100413145944.GA7716@redhat.com> <4BC48F79.5090409@siemens.com> <1271176838.16881.537.camel@edumazet-laptop> <20100413173919.GC26011@redhat.com> <1271183463.16881.545.camel@edumazet-laptop> <20100413202548.GA3582@redhat.com> <1271191086.16881.570.camel@edumazet-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1271191086.16881.570.camel@edumazet-laptop> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1623 Lines: 45 On Tue, Apr 13, 2010 at 10:38:06PM +0200, Eric Dumazet wrote: > Le mardi 13 avril 2010 ? 23:25 +0300, Michael S. Tsirkin a ?crit : > > On Tue, Apr 13, 2010 at 08:31:03PM +0200, Eric Dumazet wrote: > > > Le mardi 13 avril 2010 ? 20:39 +0300, Michael S. Tsirkin a ?crit : > > > > > > > > When a socket with inflight tx packets is closed, we dont block the > > > > > close, we only delay the socket freeing once all packets were delivered > > > > > and freed. > > > > > > > > > > > > > Which is wrong, since this is under userspace control, so you get > > > > unkillable processes. > > > > > > > > > > We do not get unkillable processes, at least with sockets I was thinking > > > about (TCP/UDP ones). > > > > > > Maybe tun sockets can behave the same ? > > > > Looks like that's what my patch does: ip_rcv seems to call > > skb_orphan too. > > Well, I was speaking of tx side, you speak of receiving side. Point is, both ip_rcv and my patch call skb_orphan. > An external flood (coming from another domain) is another problem. > > A sender might flood the 'network' inside our domain. How can we > reasonably limit the sender ? > > Maybe the answer is 'We can not', but it should be stated somewhere, so > that someone can address this point later. > And whatever's done should ideally work for tap to IP and IP to IP sockets as well, not just tap to tap. -- MST -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/