Re: Plan for improving IP_PKTINFO socket option handling

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Thu, 04 Jan 2018 13:12:11 +0100
    From:        Tom Ivar Helbekkmo <tih%hamartun.priv.no@localhost>
    Message-ID:  <m2d12plt5w.fsf%thuvia.hamartun.priv.no@localhost>

  | Since the first version with everything correctly in place is 8.99.11,
  | I'm doing this in the appropriate header file:
  | 
  | #if defined(__NetBSD_Version__) && __NetBSD_Version__ < 899001100 && defined(IP_PKTINFO)
  | #undef IP_PKTINFO
  | #endif
  | 
  | The idea is that it'll be used for our ongoing -current starting with
  | 8.99.11, and that our first official version to have the new code will
  | be NetBSD 9.

That kind of thing is possible, but unreliable, and what's more, it
is not impossible (and perhaps reasonable, once proven complete and
effective) for the changes to be pulled up to NetBSD-8 (either before
it is released or for 8.1 later or something.)

Must better would be to find some #define that was changed, or added, or
removed, if necessary by making a new one, which indicates that the
change has been made, and then test that instead of __NetBSD_Version__.

kre