On Mi, 2014-07-30 at 17:58 +0200, David Lamparter wrote:

This realigns addrconf support for the various lower-layer device types,
and removes a little bit of duplicate code.

For GRE devices, this includes a semantic change in that there is now a
ff00::/8 route installed on address autogeneration.  This was previously
missing and broke any kind of IPv6 multicast - unless another address
was configured from userspace (which then added the missing ff00::/8).

Fixes: aee80b54b235 (ipv6: generate link local address for GRE tunnel)
Signed-off-by: David Lamparter <redacted>
Cc: Hannes Frederic Sowa <redacted>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Jiri Pirko <jiri@resnulli.us>
---

This is an alternate version, yanking the switch() down and removing
dev_config/gre_config duplication.  I have no idea what rationale is behind
prefix_route - the result is a fe80::/64 route, but no address, which is not a
functioning configuration.  Jiri, you touched this just a few weeks ago, can
you comment?  (The "XXX: why is GRE special?")

Sure, it is valid. You can still use global addresses to talk to link
local addresses on the same link, even from another interface.

I prefer this patch.

Thanks,
Hannes