Re: [PATCH] net/tcp: Only produce AO/MD5 logs if there are any keys

From: Jakub Kicinski
Date: Thu Jan 04 2024 - 10:57:53 EST


On Thu, 4 Jan 2024 13:42:39 +0000 Dmitry Safonov wrote:
> User won't care about inproper hash options in the TCP header if they
> don't use neither TCP-AO nor TCP-MD5. Yet, those logs can add up in
> syslog, while not being a real concern to the host admin:
> > kernel: TCP: TCP segment has incorrect auth options set for XX.20.239.12.54681->XX.XX.90.103.80 [S]
>
> Keep silent and avoid logging when there aren't any keys in the system.
>
> Side-note: I also defined static_branch_tcp_*() helpers to avoid more
> ifdeffery, going to remove more ifdeffery further with their help.

Wouldn't we be better off converting the prints to trace points.
The chances for hitting them due to malicious packets feels much
higher than dealing with a buggy implementation in the wild.