[PATCH 2/8] network: firewalld: add networkAddHybridFirewallDRules()

[Michal Prívozník]

On 11/10/22 17:31, Eric Garver wrote:
> This factors out the firewalld pieces of the iptables + firewalld
> backend.
> 
> Signed-off-by: Eric Garver <eric at garver.life>
> ---
>  src/network/bridge_driver_linux.c | 117 ++++++++++++++++--------------
>  1 file changed, 61 insertions(+), 56 deletions(-)
> 
> diff --git a/src/network/bridge_driver_linux.c b/src/network/bridge_driver_linux.c
> index d9597d91beed..88a8e9c5fa27 100644
> --- a/src/network/bridge_driver_linux.c
> +++ b/src/network/bridge_driver_linux.c
> @@ -801,6 +801,58 @@ networkRemoveIPSpecificFirewallRules(virFirewall *fw,
>  }
>  
>  
> +static int
> +networkAddHybridFirewallDRules(virNetworkDef *def)
> +{
> +    /* if firewalld is active, try to set the "libvirt" zone. This is
> +     * desirable (for consistency) if firewalld is using the iptables
> +     * backend, but is necessary (for basic network connectivity) if
> +     * firewalld is using the nftables backend
> +     */
> +
> +    /* if the "libvirt" zone exists, then set it. If not, and
> +     * if firewalld is using the nftables backend, then we
> +     * need to log an error because the combination of
> +     * nftables + default zone means that traffic cannot be
> +     * forwarded (and even DHCP and DNS from guest to host
> +     * will probably no be permitted by the default zone
> +     */
> +    if (virFirewallDZoneExists("libvirt")) {
> +        if (virFirewallDInterfaceSetZone(def->bridge, "libvirt") < 0)
> +            return -1;
> +    } else {
> +        unsigned long version;
> +        int vresult = virFirewallDGetVersion(&version);
> +
> +        if (vresult < 0)
> +            return -1;
> +
> +        /* Support for nftables backend was added in firewalld
> +         * 0.6.0. Support for rule priorities (required by the
> +         * 'libvirt' zone, which should be installed by a
> +         * libvirt package, *not* by firewalld) was not added
> +         * until firewalld 0.7.0 (unless it was backported).
> +         */
> +        if (version >= 6000 &&
> +            virFirewallDGetBackend() == VIR_FIREWALLD_BACKEND_NFTABLES) {
> +            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> +                           _("firewalld is set to use the nftables "
> +                             "backend, but the required firewalld "
> +                             "'libvirt' zone is missing. Either set "
> +                             "the firewalld backend to 'iptables', or "
> +                             "ensure that firewalld has a 'libvirt' "
> +                             "zone by upgrading firewalld to a "
> +                             "version supporting rule priorities "
> +                             "(0.7.0+) and/or rebuilding "
> +                             "libvirt with --with-firewalld-zone"));

I know you wanted this to be plain code movement, but since you're
touching this error message you can apply our coding style rule [1] and
unbreak the message onto one, long line. All error messages are exempt
from the 80 chars rule, because it's easier to git grep them.

And on a similar note, per out deprecation policy [2], firewalld-0.6.0
or older is ancient history, thus this version check can be dropped (in
a separate commit of course).

> +            return -1;
> +        }
> +    }
> +
> +    return 0;
> +}
> +
> +

1: https://libvirt.org/coding-style.html#error-message-format
2: https://libvirt.org/platforms.html#linux-freebsd-and-macos

Michal