Stefan Berger IBM T. J. Watson Research Center, Hawthorne, NY, USA tel#: +1 914 784 7767 , fax#: +1 914 784 6225 e-mail: stefanb@us.ibm.com <tt>libvir-list-bounces@redhat.com wrote on 08/13/2010 04:21:45 PM: > [image removed] </tt> <tt>> > Re: [libvirt] [PATCH v2] nwfilter: Discard class D and E IP > addresses when sniffing packets</tt> <tt>> > Eric Blake </tt> <tt>> > to:</tt> <tt>> > Stefan Berger</tt> <tt>> > 08/13/2010 04:36 PM</tt> <tt>> > Sent by:</tt> <tt>> > libvir-list-bounces@redhat.com</tt> <tt>> > Cc:</tt> <tt>> > libvir-list</tt> <tt>> > On 08/13/2010 02:15 PM, Stefan Berger wrote: > > V2: Corrected comment and simplified mask to check for class D and E IP > > addresses > > > > When sniffing the network traffic, discard class D and E IP addresses > > when sniffing traffic. This was a reason why filters were not correctly > > rebuilt on VMs on the local 192.* network when libvirt was restarted and > > those VMs did not use a DHCP request to get its IP address. > > > > > - // skip eth. bcast and mcast addresses, > > - // and zero address in DHCP Requests > > - if ((ntohl(vmaddr)& 0xc0000000) || vmaddr == 0) { > > + // skip mcast addresses (224.0.0.0 - 239.255.255.255), > > + // class E (240.0.0.0 - 255.255.255.255, includes eth. > > + // bcast) and zero address in DHCP Requests > > + if ( (ntohl(vmaddr)& 0xe0000000) == 0xe0000000 || > ^^ > [stupid thunderbird bug - why does it reformat quoted text for no reason?]</tt> <tt>Wow, yes, that's not how I posted it.</tt> <tt>Could have also done something like (ntohl(vmaddr) >> 29) == 7, but what we have is easier to understand...</tt> <tt> > > > + vmaddr == 0) { > > ACK; looks better.</tt> <tt>Pushed.</tt> <tt> Stefan </tt>