On Thu, May 12, 2022 at 07:42:43PM +0100, Daniel P. Berrangé wrote:
On Wed, May 11, 2022 at 11:41:54AM -0400, Eric Garver wrote:
Signed-off-by: Eric Garver <eric@garver.life> --- src/network/libvirt-routed-in.policy | 11 +++++++++++ src/network/libvirt-routed-out.policy | 12 ++++++++++++ src/network/meson.build | 10 ++++++++++ 3 files changed, 33 insertions(+) create mode 100644 src/network/libvirt-routed-in.policy create mode 100644 src/network/libvirt-routed-out.policy
diff --git a/src/network/libvirt-routed-in.policy b/src/network/libvirt-routed-in.policy new file mode 100644 index 000000000000..baf8822d747c --- /dev/null +++ b/src/network/libvirt-routed-in.policy @@ -0,0 +1,11 @@ +<?xml version="1.0" encoding="utf-8"?> +<policy target="ACCEPT"> + <short>libvirt-routed-out</short> + + <description> + This policy is used to allow routed traffic to the virtual machines. + </description> + + <ingress-zone name="ANY" /> + <egress-zone name="libvirt-routed" /> +</policy>
Same as the NAT version of the policy so makes sense.
diff --git a/src/network/libvirt-routed-out.policy b/src/network/libvirt-routed-out.policy new file mode 100644 index 000000000000..efa0030569d6 --- /dev/null +++ b/src/network/libvirt-routed-out.policy @@ -0,0 +1,12 @@ +<?xml version="1.0" encoding="utf-8"?> +<policy target="ACCEPT"> + <short>libvirt-routed-out</short> + + <description> + This policy is used to allow routed virtual machine traffic to the rest of + the network. + </description> + + <ingress-zone name="libvirt-routed" /> + <egress-zone name="ANY" /> +</policy>
This is much more permissive than what I expected. Doesn't this allow the VMs to have unrestricted access to anything on the host ?
No. ANY means any zone. i.e. FORWARD. There is another symbolic zone, HOST, that is used for INPUT.
At a libvirt POV, the NAT and routed zones should be identical, with the only difference being whether masquerading is applied.
I think the additional difference is that routed allows connections originating from outside (world -> libvirt) to the VMs. There is no "in" policy for NAT for the same reason - they should always be denied. In both NAT and routed, connections originating from VMs allow the return path implicitly via conntrack state.
In terms of VM -> host, we still only want to allow the small set of services, dns, dhcp, ssh AFAIK.
Right, that's covered by the libvirt-to-host policy and is common between the NAT and routed networks.
With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|