Allow to prepend iptables rules for both IPv4 and IPv6

defaults/main.yml

@@ -2,9 +2,13 @@
 iptables__state: install
 iptables__drop_by_default: false
 iptables__allow_output_ifaces: []
+
 iptables__v4_filter_prepend: null
-iptables__v4_filter_append: null
-iptables__v4_nat: null
 iptables__v6_filter_prepend: null
+iptables__all_filter_prepend: null
+
+iptables__v4_filter_append: null
 iptables__v6_filter_append: null
+
+iptables__v4_nat: null
 iptables__v6_nat: null

templates/rules.v4

@@ -31,6 +31,8 @@ COMMIT
 
 {{ iptables__v4_filter_prepend }}
 
+{{ iptables__all_filter_prepend }}
+
 # Allow all loopback (lo) traffic and reject anything
 # to localhost that does not originate from lo.
 -A INPUT   -i lo                -j ACCEPT

templates/rules.v6

@@ -31,6 +31,8 @@ COMMIT
 
 {{ iptables__v6_filter_prepend }}
 
+{{ iptables__all_filter_prepend }}
+
 # Allow all loopback (lo) traffic and reject anything
 # to localhost that does not originate from lo.
 -A INPUT   -i lo           -j ACCEPT