Re: [PATCH net-next v5 2/5] net: vxlan: add netlink option to bind vxlan sockets to local addresses

[Ido Schimmel <idosch@nvidia.com>]

On Wed, Aug 13, 2025 at 05:46:44PM +0200, Richard Gobert wrote:
> Kuniyuki Iwashima wrote:
> > From: Richard Gobert <richardbgobert@gmail.com>
> >> @@ -4044,15 +4045,37 @@ static int vxlan_nl2conf(struct nlattr *tb[], struct nlattr *data[],
> >>  		conf->vni = vni;
> >>  	}
> >>  
> >> +	if (data[IFLA_VXLAN_LOCALBIND]) {
> >> +		if (changelink) {
> >> +			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_VXLAN_LOCALBIND], "Cannot rebind locally");
> >> +			return -EOPNOTSUPP;
> >> +		}
> > 
> > Are these two "if" necessary ?
> 
> Creating a vxlan interface without localbind then adding localbind won't
> result in the socket being rebound. I might implement this in the future,
> but for simplicity, I didn't implement this yet.

I think Kuniyuki meant that you can just call vxlan_nl2flag() without
those two "if"s because the function is a NO-OP when the attribute is
not present and it will also fail the changelink operation.

> 
> > 
> > 
> >> +
> >> +		err = vxlan_nl2flag(conf, data, IFLA_VXLAN_LOCALBIND,
> >> +				    VXLAN_F_LOCALBIND, changelink,
> >> +				    false, extack);
> >> +		if (err)
> >> +			return err;
> >> +	}
> >> +