Re: [PATCH net-next 1/2] tcp: remove per-destination timestamp cache

David Miller [off-list ref] wrote:

From: Soheil Hassas Yeganeh <redacted>
Date: Wed, 15 Mar 2017 16:30:45 -0400

quoted

Note that this cache was already broken for caching timestamps of
multiple machines behind a NAT sharing the same address.

That's the documented, well established, limitation of time-wait
recycling.

Sigh.

"don't enable this if you connect your machine to the internet".
We're not in the 1990s anymore.  Even I am behind ipv4 CG-NAT nowadays.

So I disagree and would remove this thing.

This limitation of the feature does not give us a reason to break the
feature even further as a matter of convenience, or to remove it
altogether for the same reason.

Please, instead, fix the bug that was introduced.

AFAIU we only have two alternatives, removal of the randomization feature
or switch to a offset computed via hash(saddr, daddr, secret).

Unless there are more comments I'll look into doing the latter tomorrow.