Re: [PATCH net-next 3/9] ipv6: fib_rules: Add flow label support

[Ido Schimmel <idosch@nvidia.com>]

On Wed, Dec 18, 2024 at 07:05:09PM -0800, Jakub Kicinski wrote:
> On Mon, 16 Dec 2024 19:11:55 +0200 Ido Schimmel wrote:
> > +	if (flowlabel_mask & ~IPV6_FLOWLABEL_MASK) {
> > +		NL_SET_ERR_MSG_ATTR(extack, tb[FRA_FLOWLABEL_MASK],
> > +				    "Invalid flow label mask");
> > +		return -EINVAL;
> > +	}
> 
> Have you considered NLA_POLICY_MASK() ?
> Technically it does support be32, but we'd need to bswap ~IPV6_FLOWLABEL_MASK
> and you need the helper anyway... so up to you.

I did consider it, but I preferred to have all the checks at the same
place in the IPv6 code instead of having it split between IPv6 and core

> 
> > +	if (flowlabel & ~flowlabel_mask) {
> > +		NL_SET_ERR_MSG(extack, "Flow label and mask do not match");
> > +		return -EINVAL;
> > +	}