Gur Stavi wrote: > > > > If we don't care about opening up fanout groups to ETH_P_NONE, then > > patch v2 seems sufficient. If explicitly blocking this, the ENXIO > > return can be added, but ideally without touching the other lines. > > I don't think that allowing ETH_P_NONE is relevant. > In my opinion the 2 options that should be considered to fail > fanout_add are: > 1. Testing proto == 0 > 2. Testing proto == 0 || ifindex == -1 > > The only corner case that is caught by [2] and missed by [1] is > the "unlisted" case during do_bind. It is such a rare case that > probably no one will ever encounter bind "unlisted" followed by > FANOUT_ADD. And this is not a dangerous corner case that leads to > system crash. > > However, being a purist, I see the major goal of code review to promote > correctness by identifying corner cases while improving style is a > secondary priority. Since we did identify this corner case in our > discussion I think we should still use [2]. > I don't consider the code complex. In fact, to me, the ifindex clause > is a more understandable direct reason for failure than the proto which > is indirect. Having the ifindex clause helps figuring out the proto > clause. It's interesting that the unlisted fix does not return ENODEV, but returns success and leaves the socket in an unbound state, equivalent to binding to ETH_P_NONE and ifindex 0. This seems surprising behavior to the caller. On rereading that, I still do not see a purpose of special ifindex -1.
