Re: [PATCH v4] net: ipv6: seg6: report lwtunnel setup errors via extack

[Gabriel Goller]

On 06.10.2026 17:43, Andrea Mayer wrote:
> On Mon,  5 Oct 2026 16:06:34 +0200
> Gabriel Goller <g.goller@xxxxxxxxxxx> wrote:
> 
> Hi Gabriel,
> 
> thanks for the v4. +1 to Jakub on _MISS. I also have two comments on
> the message text.
> 
> > [snip]
> >  	switch (tuninfo->mode) {
> >  	case SEG6_IPTUN_MODE_INLINE:
> > -		if (family != AF_INET6)
> > +		if (family != AF_INET6) {
> > +			NL_SET_ERR_MSG_ATTR(extack, tb[SEG6_IPTUNNEL_SRH],
> > +					    "inline mode requires an IPv6 route");
> >  			return -EINVAL;
> > +		}
> 
> This message is also returned for an IPv4 nexthop object, where there
> is no route, for example:
> 
>   ip -4 nexthop add id 1 encap seg6 mode inline segs fc00::1 dev dummy0
> 
> What about "inline mode requires the IPv6 address family"?
> 
> > [snip]
> >  	/* verify that SRH is consistent */
> > -	if (!seg6_validate_srh(tuninfo->srh, tuninfo_len - sizeof(*tuninfo), false))
> > +	if (!seg6_validate_srh(tuninfo->srh, tuninfo_len - sizeof(*tuninfo),
> > +			       false)) {
> > +		NL_SET_ERR_MSG_ATTR(extack, tb[SEG6_IPTUNNEL_SRH],
> > +				    "invalid SRv6 segment routing header");
> >  		return -EINVAL;
> > +	}
> 
> A nit: the same header is "SRv6 segment routing header" here and
> "SRv6 SRH" in the other messages of seg6_build_state(). What about
> using the name from the title of RFC 8754 in the extack messages,
> for example:
> 
>   "invalid SRv6 segment routing header"
>     -> "invalid IPv6 Segment Routing Header"
> 
> Thanks,
> Andrea

Agree with everything
Thanks for the review!

Gabriel