* `ipsec_policy`: Sets the ipsec policy type. Valid values are 'none', 'ipsec'. Requires the `ipsec_policy` feature.
+* `ipset`: Matches IP sets. Value must be `ipset_name (src|dst|src,dst)` and can be negated by putting ! in front. Requires ipset kernel module.
+
* `isfirstfrag`: If true, matches when the packet is the first fragment of a fragmented ipv6 packet. Cannot be negated. Supported by ipv6 only. Valid values are 'true', 'false'. Requires the `isfirstfrag` feature.
* `isfragment`: If 'true', matches when the packet is a tcp fragment of a fragmented packet. Supported by iptables only. Valid values are 'true', 'false'. Requires features `isfragment`.
newproperty(:ipset, :required_features => :ipset) do
desc <<-EOS
Matches against the specified ipset list.
+ Requires ipset kernel module.
The value is the name of the blacklist, followed by a space, and then
'src' and/or 'dst' separated by a comma.
For example: 'blacklist src,dst'