Re: [PATCH net-next v3] net/ipv6: Introduce accept_unsolicited_na knob to implement router-side changes for RFC9131

[Eric Dumazet]

On 4/13/22 15:00, David Ahern wrote:
> On 4/13/22 3:22 PM, Eric Dumazet wrote:
> > On 4/13/22 07:34, Arun Ajith S wrote:
> > > Add a new neighbour cache entry in STALE state for routers on receiving
> > > an unsolicited (gratuitous) neighbour advertisement with
> > > target link-layer-address option specified.
> > > This is similar to the arp_accept configuration for IPv4.
> > > A new sysctl endpoint is created to turn on this behaviour:
> > > /proc/sys/net/ipv6/conf/interface/accept_unsolicited_na.
> >
> > Do we really need to expose this to /proc/sys, for every interface added
> > in the host ?
> >
> > /proc files creations/deletion cost a lot in environments
> > adding/deleting netns very often.
> agree with the general intent (along with the increasing memory costs).
> I do think this case should be done as a /proc/sys entry for consistency
> with both ARP and existing related NA settings.
>
> > I would prefer using NETLINK attributes, a single recvmsg() syscall can
> > fetch/set hundreds of them.
> What do you have in mind here? A link attribute managed through `ip link
> set`?


Yes, something like that, if this is a netdevice/link attribute.