On Mon, Jan 15, 2018 at 07:43:18PM +0100, Lorenzo Bianconi wrote:
> > On Sun, Jan 14, 2018 at 03:50:56PM +0100, Lorenzo Bianconi wrote:
> >> --- a/net/l2tp/l2tp_core.h
> >> +++ b/net/l2tp/l2tp_core.h
> >> @@ -302,6 +302,17 @@ static inline void l2tp_session_dec_refcount(struct
> >> l2tp_session *session)
> >> l2tp_session_free(session);
> >> }
> >>
> >> +static inline int l2tp_get_l2specific_len(struct l2tp_session *session)
> >> +{
> >> + switch (session->l2specific_type) {
> >> + case L2TP_L2SPECTYPE_NONE:
> >> + return 0;
> >> + case L2TP_L2SPECTYPE_DEFAULT:
> >> + default:
> >> + return 4;
> >> + }
> >> +}
> >>
> > The data path only compares ->l2specific_type to L2SPECTYPE_DEFAULT and
> > treats any other value as L2SPECTYPE_NONE. Therefore, we should keep
> > this logic here and return 0 for unknown types.
>
> The data path only compares l2specific_type to L2SPECTYPE_DEFAULT
> since in the other supported case (L2SPECTYPE_NONE) there is no action
> required. Moreover L2SPECTYPE_DEFAULT is default configured value if
> the user does not provide any value for l2specific_type so there are
> no 'unknown' types and I thought L2TP_L2SPECTYPE_DEFAULT was a better
> choice for default value
>
Yes, but what I meant is that the data patch treats unknow values as
L2SPECTYPE_NONE, while l2tp_get_l2specific_len() now treats them as
L2TP_L2SPECTYPE_DEFAULT. I'd just prefer to avoid that inconsistency;
it makes it easier to reason about the code.
But if you really prefer L2SPECTYPE_DEFAULT, then fine. Unless someone
messes with new l2spec types, we should never reach this case.
