Hi Dan,
On Sat, May 06, 2017 at 08:09:49PM -0400, Dan wrote:
On Fri, May 5, 2017 at 4:29 PM, Nicolas Bock <nicolasbock@xxxxxxxxx> wrote:
Hi,
I am running a webserver on the libvirt host and would like to add a
nwfilter such that a VM can access that server. The corresponding iptables
rule would look like this:
iptables --append INPUT --in-interface virbr0 --destination 192.168.122.1
--protocol tcp --dport 80 --jump ACCEPT
where the network is using virbr0 and sits at 192.168.122.1. I don't want
to hardcode the host IP address in the nwfilter so that I can use that
filter for other networks. Is it possible to reference the host's IP
address in the filter?
Thanks!
Nick
Hi Nick,
I used to have similar question before too. Not sure if this could be
helpful for you, Probably just use arp or arpscan. But to be more
specific, if the domain name of the client (assuming you want to
confine HTTP service to only a selected few clients, e.g.,
192.168.122.1 in your case) is known, you probably could do
$ virsh domiflist DOMAIN
In particular, to get the IP address of a domain, it is something like the
following:
$ for MAC in `virsh domiflist <DOMAIN> | grep -o -E
"([0-9a-f]{2}:){5}([0-9a-f]{2})"` ; do
arp -e | grep $MAC | grep -o -P
"^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}" ;
done
Alternatively, if the NETWORK name is known, IP addr can be obtained
directly with
$ virsh net-dhcp-leases NETWORK
Another way to the get IP addr, if qemu guest agent is installed on the
client,
$ virsh domifaddr DOMAIN
So that you can pass IP to the XML, and somehow you can trigger the update
of NWFILTER with some magic, quite a hack.
Thanks! I was hoping for something less hacky :)
Or, you could just use client's MAC addr to define the filter:
https://libvirt.org/formatnwfilter.html#nwfelemsRulesProtoMAC
But I don't think there is direct way to specify a client's domain name in
the NWFILTER XML definition as of now.
P.S. I am new to libvirt, so everything above could be wrong.
Dan
_______________________________________________
libvirt-users mailing list
libvirt-users@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvirt-users
