libvirt users - Jan 2017 - Re: Default firewall rules and forwarding to a guest

Hello,


I am trying to understand how libvirt firewall rules are loaded as I have
firewalld and iptables services are disabled.


Where is the configuration files for firewall and NAT  rules for libvirt?

How can I load default firewall rules if I mess things up


Also I have realized that followings is default


ACCEPT     all  --  0.0.0.0/0            192.168.122.0/24     ctstate
RELATED,ESTABLISHED


but If I am to forward a port for a real IP to internal guest machine I need


ACCEPT     all  --  0.0.0.0/0            192.168.122.0/24     state
NEW,RELATED,ESTABLISHED


(NEW state is required) and also of course a forwarding rule


iptables -t nat -I PREROUTING -p tcp --dport 3389 -j DNAT --to-destination
192.168.122.16:3389


Is there a place I can make this rules static with LibVirt (not playing with
firewalld  and/or iptables service for Centos 7)


Regards.

On 12/22/2016 09:48 AM, Omer Aldemir wrote:
>
> Hello,
>
>
> I am trying to understand how libvirt firewall rules are loaded as I 
> have firewalld and iptables services are disabled.
>
libvirt will add its iptables rules via firewalld if firewalld is 
enabled and running, otherwise it executes iptables commands directly.

w
>
>
> Where is the configuration files for firewall and NAT  rules for libvirt?
>
There are no configuration files for the iptables rules that libvirt 
adds. The simple set of rules that is added is fixed for each type of 
libvirt network - NAT, routed, and isolated. Here is a description of 
exactly what is added for each of these types of network:

    https://libvirt.org/firewall.html

(actually I just realized that I forgot to add information there about a 
new network forwarding type I recently added - "open", which
doesn't add
*any* iptables rules - this is intended for those who want to do their 
own iptables setup for libvirt networks, outside of libvirt.)
> How can I load default firewall rules if I mess things up
>
To reload all the iptables rules for all active libvirt networks, just 
restart the libvirtd service.
>
> Also I have realized that followings is default
>
>
> ACCEPT     all  --  0.0.0.0/0 192.168.122.0/24     ctstate 
> RELATED,ESTABLISHED
>
>
> but If I am to forward a port for a real IP to internal guest 
> machine I need
>
>
> ACCEPT     all  --  0.0.0.0/0 192.168.122.0/24     state 
> NEW,RELATED,ESTABLISHED
>
>
> (NEW state is required) and also of course a forwarding rule
>
>
> iptables -t nat -I PREROUTING -p tcp --dport 3389 -j DNAT 
> --to-destination 192.168.122.16:3389
>
>
> Is there a place I can make this rules static with LibVirt (not 
> playing with firewalld  and/or iptables service for Centos 7)
>
The best that can be done with current libvirt is to create a "hook" 
script similar to the one described here:

https://wiki.libvirt.org/page/Networking#Forwarding_Incoming_Connections

(That worked the last time I tried it, but that was at least 3 years 
ago. The python script available as a link from that page is newer and 
promises to be easier to understand (maybe))
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Thanks for the answers i think open network type is not available yet on the
version that comes with rhel7

On 3 Jan 2017, at 22:06, Laine Stump
<laine@laine.org<mailto:laine@laine.org>> wrote:

On 12/22/2016 09:48 AM, Omer Aldemir wrote:

Hello,


I am trying to understand how libvirt firewall rules are loaded as I have
firewalld and iptables services are disabled.

libvirt will add its iptables rules via firewalld if firewalld is enabled and
running, otherwise it executes iptables commands directly.

w


Where is the configuration files for firewall and NAT  rules for libvirt?

There are no configuration files for the iptables rules that libvirt adds. The
simple set of rules that is added is fixed for each type of libvirt network -
NAT, routed, and isolated. Here is a description of exactly what is added for
each of these types of network:

   https://libvirt.org/firewall.html

(actually I just realized that I forgot to add information there about a new
network forwarding type I recently added - "open", which doesn't
add *any* iptables rules - this is intended for those who want to do their own
iptables setup for libvirt networks, outside of libvirt.)


How can I load default firewall rules if I mess things up

To reload all the iptables rules for all active libvirt networks, just restart
the libvirtd service.



Also I have realized that followings is default


ACCEPT     all  --  0.0.0.0/0            192.168.122.0/24     ctstate
RELATED,ESTABLISHED


but If I am to forward a port for a real IP to internal guest machine I need


ACCEPT     all  --  0.0.0.0/0            192.168.122.0/24     state
NEW,RELATED,ESTABLISHED


(NEW state is required) and also of course a forwarding rule


iptables -t nat -I PREROUTING -p tcp --dport 3389 -j DNAT --to-destination
192.168.122.16:3389


Is there a place I can make this rules static with LibVirt (not playing with
firewalld  and/or iptables service for Centos 7)

The best that can be done with current libvirt is to create a "hook"
script similar to the one described here:

https://wiki.libvirt.org/page/Networking#Forwarding_Incoming_Connections

(That worked the last time I tried it, but that was at least 3 years ago. The
python script available as a link from that page is newer and promises to be
easier to understand (maybe))