On Thu, 14 Jan 2021 14:50:04 -0800 Cong Wang wrote:
> > static int fl_set_vxlan_opt(const struct nlattr *nla, struct fl_flow_key
> > *key,
> > int depth, int option_len,
> > struct netlink_ext_ack *extack)
> > {
> > struct nlattr *tb[TCA_FLOWER_KEY_ENC_OPT_VXLAN_MAX + 1];
> > struct vxlan_metadata *md;
> > int err;
> >
> > md = (struct vxlan_metadata
> > *)&key->enc_opts.data[key->enc_opts.len];
> > memset(md, 0xff, sizeof(*md));
> >
> > if (!depth)
> > return sizeof(*md);
> > ^^^^^^^^^^^^^^^^^^^
> >
> > The mask is filled with all 1s if attribute is not provided.
>
> Hmm, then what is the length comparison check for?
>
> fl_set_vxlan_opt() either turns negative or sizeof(*md), and negitve
> is already checked when it returns, so when we hit the length comparison
> it is always equal. So it must be redundant.
>
> (Note, I am only talking about the vxlan case you pick here, because the
> geneve case is different, as it returns different sizes.)
Good question 🤷🏻♂️🤷🏻♂️ I'd guess GENEVE came first and and then
people copy / pasted the code structure other tunnel types?
