Re: [RFC net-next] netlink: specs: add genetlink-legacy spec for GTP

[Anil Kaushik]

Thanks Jakub

On Thu, Oct 8, 2026 at 4:48 AM Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
>
> On Thu,  1 Oct 2026 09:02:50 +0000 Anil Kaushik wrote:
> > The GTP (GPRS Tunnelling Protocol, user plane) generic netlink family
> > has no YAML specification under Documentation/netlink/specs/, so it
> > cannot be consumed by the ynl tooling used for user-space clients,
> > documentation and selftests.
> >
> > Add a genetlink-legacy spec describing the existing family: the PDP
> > context management commands (NEWPDP, DELPDP, GETPDP) and the GTP-U echo
> > request (ECHOREQ), the GTPA_* attribute set, and the "gtp" multicast
> > group. The spec is derived directly from include/uapi/linux/gtp.h and
> > the gtp_genl_policy / gtp_genl_ops tables in drivers/net/gtp.c; command
> > and attribute values match the existing uapi one-to-one.
> >
> > This only adds the description; there is no kernel code or uapi change.
>
> Do you have any plans to use this?

Yes. v2 adds a self test that uses the spec: it creates a gtp device, adds a
PDP context with newpdp, checks getpdp lists it, then delpdp removes it.
Writing it also surfaced a real bug in the driver (the get/dump replies put
the family id in the command field instead of a GTP_CMD_* value), so v2 is
now a small set of items: fix, spec, and the self test.

> Why send it as RFC and not PATCH?
I used RFC intentionally, to get feedback on whether a genetlink-legacy spec
for an older family was required.

Regards
Anil