From: Guillaume Nault <g.nault@xxxxxxxxxxxx>
Date: Wed, 23 May 2018 15:57:08 +0200
> I'd rather add
> + if (cmd == PPPIOCDETACH) {
> + err = -EINVAL;
> + goto out;
> + }
>
> Making PPPIOCDETACH unknown to ppp_generic means that the ioctl would
> be handled by the underlying channel when pf->kind == CHANNEL (see the
> chan->ops->ioctl() call further down). That shouldn't be a problem per
> se, but even though PPPIOCDETACH is unsupported, I feel that it should
> remain a ppp_generic thing. I don't really want its value to be reused
> for other purposes in the future or have different behaviour depending
> on the underlying channel.
>
> Also PPPIOCDETACH can already fail with -EINVAL. Therefore, if ever
> there really were programs out there using this call, they'd already
> have to handle this case. Unconditionally returning -EINVAL would
> further minimise possibilities for breakage.
I agree.
