netdev - Re: inter-qdisc communication?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20220826170632.4c975f21@kernel.org>
Date:   Fri, 26 Aug 2022 17:06:32 -0700
From:   Jakub Kicinski <kuba@...nel.org>
To:     Thorsten Glaser <t.glaser@...ent.de>
Cc:     netdev@...r.kernel.org
Subject: Re: inter-qdisc communication?

On Fri, 26 Aug 2022 21:34:47 +0200 (CEST) Thorsten Glaser wrote:
> Hi,
> 
> is it possible for qdiscs to communicate with each other?
> 
> For example, if I have a normal egress qdisc and an ingress
> qdisc, how could I “share” configuration values so that e.g.
> a “tc change” can affect both in one run?
> 
> Use case: we have a normal egress qdisc that does a lot of
> things. Now we add artificial latency, and we need to do that
> on ingress as well, for symmetry, obviously, so I’ll write a
> small qdisc that does just that for ingress. But we’re already
> firing a “tc change” to the egress qdisc every few ms or so,
> and I don’t want to double that overhead.

How do you add latency on ingress? 🤔 
The ingress qdisc is just a stub to hook classifiers/actions.