From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:49470) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UL0Qz-0005oh-NF for qemu-devel@nongnu.org; Wed, 27 Mar 2013 20:11:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UL0Qy-0007JV-Nu for qemu-devel@nongnu.org; Wed, 27 Mar 2013 20:11:13 -0400 Received: from mail-qc0-x235.google.com ([2607:f8b0:400d:c01::235]:37321) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UL0Qy-0007JR-Jn for qemu-devel@nongnu.org; Wed, 27 Mar 2013 20:11:12 -0400 Received: by mail-qc0-f181.google.com with SMTP id a22so3974550qcs.12 for ; Wed, 27 Mar 2013 17:11:12 -0700 (PDT) From: Anthony Liguori In-Reply-To: References: Date: Wed, 27 Mar 2013 19:11:04 -0500 Message-ID: <874nfw2xk7.fsf@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Subject: Re: [Qemu-devel] Connection breaks for macvtap List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richa Marwaha , qemu-devel@nongnu.org Richa Marwaha writes: > Hi > > I am trying to run some KVM fuzz testing where I have a tool called scapy > running on my host and guest which changes the data in the IP header > of the FWIW, I don't think you'll gain a lot from this. QEMU does not ever look at a packet beyond the MAC address (and perhaps any vlan tags in the ethernet header). That far up the stack is strictly application/network infrastructure land. So if your goal is to fuzz test the Linux networking code, then this approach is fine. But it's unlikely to do anything useful with QEMU itself. > packages and send it out to the host and vice versa. I have macvtap setup > on my host (have tried both VEPA and Bridge mode). Unless you have an explicit reason to use it, I'd steer away from macvtap. It's not commonly used. > My ssh connection to my guest breaks down after having send just 22 > packets If you're munging random IP packets, you're going to lose connections :-) That's pretty much a given. I'm not surprised at all it happens this quickly. > and also the gnome crashes. I see the following message in the dmesg > > dbus[545]: [system] Rejected send message, 2 matched rules; > type="method_return", sender=":1.0" (uid=0 pid=499 > comm="/usr/lib/systemd/systemd-logind ") interface="(unset)" > member="(unset)" error name="(unset)" requested_reply="0" > destination=":1.17" (uid=42 pid=658 comm="/usr/bin/gnome-session -f --debug > ") I don't know what this is but if you were doing something like remoting X over an ssh session, this wouldn't be much of a surprise. Regards, Anthony Liguori > > The connection to the guest restart but wanted to know what makes it > breakdown. > > Regards, > Richa Marwaha