Re: [PATCH v3 net-next 1/3] ipv6: remove dst_allfrag test on ipv6 output

From: Eric Dumazet
Date: Fri Oct 20 2023 - 02:06:25 EST


On Fri, Oct 20, 2023 at 7:32 AM Yan Zhai <yan@xxxxxxxxxxxxxx> wrote:
>
> dst_allfrag was added before the first git commit:
>
> https://www.mail-archive.com/bk-commits-head@xxxxxxxxxxxxxxx/msg03399.html
>
> The feature would send packets to the fragmentation path if a box
> receives a PMTU value with less than 1280 byte. However, since commit
> 9d289715eb5c ("ipv6: stop sending PTB packets for MTU < 1280"), such
> message would be simply discarded. The feature flag is neither supported
> in iproute2 utility. In theory one can still manipulate it with direct
> netlink message, but it is not ideal because it was based on obsoleted
> guidance of RFC-2460 (replaced by RFC-8200).
>
> The feature test would always return false at the moment, so remove it
> from the output path.

What about other callers of dst_allfrag() ?

This feature seems broken atm.