Re: [libvirt] [PATCH v2] nwfilter: Discard class D and E IP addresses when sniffing packets
Stefan Berger
IBM T. J. Watson Research Center,
Hawthorne, NY, USA
tel#: +1 914 784 7767 ,
fax#: +1 914 784 6225
e-mail: stefanb(a)us.ibm.com
libvir-list-bounces(a)redhat.com wrote on 08/13/2010 04:21:45 PM:
[image removed]
Re: [libvirt] [PATCH v2] nwfilter: Discard class D and E IP
addresses when sniffing packets
Eric Blake
to:
Stefan Berger
08/13/2010 04:36 PM
Sent by:
libvir-list-bounces(a)redhat.com
Cc:
libvir-list
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?]
Wow, yes, that's not how I posted it.
Could have also done something like (ntohl(vmaddr) >> 29) == 7, but what
we have is easier to understand...
> + vmaddr == 0) {
ACK; looks better.
Pushed.
Stefan
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