Along comes... xt_u32, a revamped ipt_u32 from POM-NG,
Plus:

    *	2007-06-02: added ipv6 support

    *	2007-06-05: uses kmalloc for the big buffer

    *   2007-06-05: added inversion

    *   2007-06-20: use skb_copy_bits() and get rid of the big buffer
        and lock (suggested by Pablo Neira Ayuso)
Signed-off-by: NJan Engelhardt <jengelh@gmx.de>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>