2022-04-14 05:38:23

by Eric Dumazet

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


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.