tree c34dc937d87f33c686a82c9fc3f2ac542dea2829
parent d46bcd236e93432c894a939f4e5810dc5e9b4974
author Harald Welte <laforge@gnumonks.org> 1502303332 +0200
committer Harald Welte <laforge@gnumonks.org> 1502441160 +0200

IPv6: Support PCO for IPv6 DNS addresses

In IPv6, DNS server information is not passed along as IPCP6 like
in IPv5 with IPCP.  The reason is that IPCP6 (for PPP) doesn't
support passing DNS server information.  Rather, the relevant RFCs
indicate DHCPv6 should be used even over point-to-point links.

3GPP decided to avoid DHCPv6 dependency for stateless autoconfiguration
(the only mandatory IPv6 configuration mechanism) and added some new
non-PPP-style PCO information elements ("containers") which can among
other things inform a MS about IPV6 DNS servers.

That same mechanism can also be used to inform the MS about IPv4 DNS
servers, so for IPv4 there are now two competing mechanisms: IPCP and
the new "native" PCO container.  With this patch, we support both
for IPv4.

Change-Id: I21499afd61def8c925f7838bde76f34d28214b56