From: Gao feng <redacted>
Date: Mon, 19 Mar 2012 08:49:51 +0800

BUT what confuse me is that, in func ip6_rt_copy should we do
rt6_set_from in any case or only when the ort has flag RTF_ADDRCONF
and RTF_DEFAULT?

Your guess is as good as mine, unfortunately.  A lot of code in
this area is hard to decipher.

For example, I've spent the past several months trying to figure out
which kinds of ipv6 routes have explicit neighbour entries attached at
route insert time, which do not, etc.