The "nomatch" keyword and option is added to the hash:*net* types,
by which one can add exception entries to sets. Example:

        ipset create test hash:net
        ipset add test 192.168.0/24
        ipset add test 192.168.0/30 nomatch

In this case the IP addresses from 192.168.0/24 except 192.168.0/30
match the elements of the set.
Signed-off-by: NJozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

ipset is actually using NFPROTO values rather than AF (xt_set passes
that along).
Signed-off-by: NJan Engelhardt <jengelh@medozas.de>
Signed-off-by: NJozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

If overlapping networks with different interfaces was added to
the set, the type did not handle it properly. Example

    ipset create test hash:net,iface
    ipset add test 192.168.0.0/16,eth0
    ipset add test 192.168.0.0/24,eth1

Now, if a packet was sent from 192.168.0.0/24,eth0, the type returned
a match.

In the patch the algorithm is fixed in order to correctly handle
overlapping networks.

Limitation: the same network cannot be stored with more than 64 different
interfaces in a single set.
Signed-off-by: NJozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

Signed-off-by: NJozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

The hash:net,iface type makes possible to store network address and
interface name pairs in a set. It's mostly suitable for egress
and ingress filtering. Examples:

        # ipset create test hash:net,iface
        # ipset add test 192.168.0.0/16,eth0
        # ipset add test 192.168.0.0/24,eth1
Signed-off-by: NJozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: NPatrick McHardy <kaber@trash.net>