Re: [PATCH net-next] Revert "net/ipv6: add sysctl option accept_ra_min_hop_limit"

[Sabrina Dubroca <sd@queasysnail.net>]

Hello,

2015-09-10, 10:54:38 +0800, Hangbin Liu wrote:
> > Can we still modify the behavior of this sysctl? It's already been in
> > Linus's tree for a while, but if we can, I would rather restrict the
> > values we let the user write to accept_ra_min_hop_limit, as anything
> > outside [0..255] does not really make sense.
> 
> Yes, so the checked if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
> ra_msg->icmph.icmp6_hop_limit)  make sure we only update the value between
> [1..255].

I was thinking of returning -EINVAL when the user tries to set it to
300, using proc_dointvec_minmax.


> > Allowing an RA to update the hop limit if
> >
> >    current hop limit < RA.hop_limit < accept_ra_min_hop_limit
> >
> > might also be desirable, but I'm not so sure about this case.
> 
> Yes, and we also should allow an RA to update the hop limit if
> 
> accept_ra_min_hop_limit <= RA.hop_limit < current hop limit
> 
> e.g accept_ra_min_hop_limit = RA.hop_limit =64, current hop limit = 128

Yes, that's what we're doing at the moment, and I would leave it as is.


Thanks,

-- 
Sabrina