Fix for the NAT-T ABI change

["S.P.Zeidler" <spz%serpens.de@localhost>]

Dear all,

please review and test the patch at
http://www.netbsd.org/~spz/ipsec-natt-abi-fix.diff

The patch leans on vanhus patch for FreeBSD, but differs.

IPSEC + IPSEC-NAT-T: tested to work when not using NAT-T
(I use IPSEC but I have no counterpoint to test NAT-T against at present)

FAST_IPSEC + IPSEC-NAT-T: does not seem to work less than without the patch
IPv4 seems to work.
IPv6: I can ping6 my tunnel gateway, but nothing beyond it. It seems
to try to open a ipsec conversation to the target itself instead of
tunnelling, which is Not Allowed (and not expected).
Starting firefox (with or without the NAT-T patch) gets me a panic with
ensuing panic of ddb (with the NAT-T patch it's LOCKDEBUG, not convinced
that that is resembling the reason). I'll test FAST_IPSEC some more later.

regards,
        spz
-- 
spz%serpens.de@localhost (S.P.Zeidler)