ipip: reject unsupported configurations in fill_forward_path

The ipip fill_forward_path callback currently does not check for
configurations that cannot be offloaded to hardware:

- Collect metadata (flow-based) tunnels have no fixed destination
  and rely on per-packet tunnel metadata, so the forward path
  cannot be pre-computed.

- TOS inheritance (parms.iph.tos & 0x1) requires copying the outer
  TOS from the inner packet at encapsulation time, which is not
  known during forward path resolution.

Return -EOPNOTSUPP for both cases to fall back to the software
forwarding path.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260725-ipip-fill-forward-path-fix-v1-1-bc69fd3127d5@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

0 files changed, 0 insertions, 0 deletions