Re: [PATCH net-next v2] net: ipv6: seg6: report lwtunnel setup errors via extack

[Andrea Mayer]

On Tue, 22 Sep 2026 11:08:33 +0200
Gabriel Goller <g.goller@xxxxxxxxxxx> wrote:

Hi Gabriel,

> seg6_build_state() rejected invalid configurations with a generic -EINVAL, so
> "ip route add ... encap seg6 ..." always reported "Invalid argument".
> 
> Attach an extack message to each of them. The checks themselves and their return
> values are unchanged.
> 
> Signed-off-by: Gabriel Goller <g.goller@xxxxxxxxxxx>

The commit message stays in the changelog, so wrapping the body at 75
columns would be better.

> ---
> 
> v2 (https://lore.kernel.org/netdev/20260918153544.1178884-1-g.goller@xxxxxxxxxxx/):
>  * dropped tests
> 
>  net/ipv6/seg6_iptunnel.c | 25 ++++++++++++++++++++-----
>  1 file changed, 20 insertions(+), 5 deletions(-)
> 
> diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c
> index 61c6a27bf202..e7f75970e26e 100644
> --- a/net/ipv6/seg6_iptunnel.c
> +++ b/net/ipv6/seg6_iptunnel.c
> @@ -756,8 +756,12 @@ static int seg6_build_state(struct net *net, struct nlattr *nla,
>  	struct seg6_lwt *slwt;
>  	int err;
>  
> -	if (family != AF_INET && family != AF_INET6)
> +	if (family != AF_INET && family != AF_INET6) {
> +		NL_SET_ERR_MSG(
> +			extack,
> +			"unsupported address family for SRv6 encapsulation");
>  		return -EINVAL;
> +	}

checkpatch flags this line ("Lines should not end with a '('"). The
two-line form used in the rest of the file would be better:

	NL_SET_ERR_MSG(extack,
		       "unsupported address family for SRv6 encapsulation");

The string goes a bit over 80 columns but should stay on one line for grep.

A side note: the source_inline bot failure looks like a false positive,
the script matches "inline" inside the string literal.

Thanks,
Andrea