[Cake] Using firewall connmarks as tin selectors

[Toke Høiland-Jørgensen]

Kevin Darbyshire-Bryant <kevin at darbyshire-bryant.me.uk> writes:

> How unpopular would the idea of having cake look at skb->mark directly be?
>
> https://github.com/ldir-EDB0/sch_cake/commit/64d0e6ac9368a271221db888ab91a367fcd37ae1
>
> https://github.com/ldir-EDB0/tc-adv/commit/4f16ae5d588d44f8a5c83fe2f2b7dcad97843cbc

Hmm, not impossible, but seeing as we already have a way to achieve that
with BPF, is it really needed?

> I did the equivalent in eBPF here
> https://github.com/ldir-EDB0/cls_bpf_connmark_to_caketin but I can’t
> work out how to make the major number a tc command line argument into
> the BPF code.

You can't, but you can set the major number explicitly when you create
the qdisc:

$ sudo tc qdisc replace dev eth0 root handle 1: cake
$ tc qdisc show dev eth0
qdisc cake 1: root refcnt 2 bandwidth unlimited diffserv3 triple-isolate nonat nowash no-ack-filter split-gso rtt 100.0ms raw overhead 0


-Toke