On Tue, Jan 31, 2017 at 11:57:05PM +0200, Julian Anastasov wrote:
>
> static unsigned int ip6_blackhole_mtu(const struct dst_entry *dst)
> diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
> index 177e208..c010ee0 100644
> --- a/net/xfrm/xfrm_policy.c
> +++ b/net/xfrm/xfrm_policy.c
> @@ -2856,6 +2856,20 @@ static struct neighbour *xfrm_neigh_lookup(const
> struct dst_entry *dst,
> return dst->path->ops->neigh_lookup(dst, skb, daddr);
> }
>
> +static void xfrm_confirm_neigh(const struct dst_entry *dst, const void
> *daddr)
> +{
> + const struct dst_entry *path = dst->path;
> +
> + if (path == dst) {
I think path can not be equal to dst here, otherwise we would
have an infinite recursion.
> + dst->ops->confirm_neigh(dst, daddr);
> + } else {
> + /* daddr can be from different family and we need the
> + * tunnel address. How to get it?
> + */
This is only called on a xfrm_dst, so you should have dst->xfrm set.
You can get the daddr of this transform with:
xfrm_address_t *daddr = &xfrm->id.daddr;
> + path->ops->confirm_neigh(path, NULL);
I think here it is better to go through the whole chain
of transformations with
child->ops->confirm_neigh(path, daddr);
> + }
> +}
> +
> int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
> {
> int err = 0;
> @@ -2882,6 +2896,8 @@ int xfrm_policy_register_afinfo(struct
> xfrm_policy_afinfo *afinfo)
> dst_ops->link_failure = xfrm_link_failure;
> if (likely(dst_ops->neigh_lookup == NULL))
> dst_ops->neigh_lookup = xfrm_neigh_lookup;
> + if (likely(!dst_ops->confirm_neigh))
> + dst_ops->confirm_neigh = xfrm_confirm_neigh;
We also have address family depended dst_ops, look for
xfrm4_dst_ops_template/xfrm6_dst_ops_template.
