IPV6_PKTINFO/recvfromto

[Alan DeKok]

Alexander Clouter wrote:
> Turns out 'struct in6_pktinfo' is a GNU extension[1] and so you need to 
> define _GNU_SOURCE when ./configure is running otherwise you get 
> HAVE_IN6_PKTINFO is undefined.  I just gave it a whirl, config.cache 
> shows 'yes' now for the presence of ipi6_pktinfo:

  I think that check isn't really necessary.  If the "IPV6_PKTINFO"
definition exists, the compiler can be pretty sure that the "struct
in6_pktinfo" entry exists.

  I've pushed some changes to the v2.1.x branch which should help.  They
should also fix Linux kernel version issues with using IPV6_RECVPKTINFO
versus IPV6_PKTINFO.

  The only thing the changes *don't* do is update src/lib/radius.c to
allow IPv6 for "udpfromto" sockets.

  If the rest of the changes work for you, I can then re-add the IPv6
support in src/lib/radius.c.

  Alan DeKok.