[Cake] Using firewall connmarks as tin selectors

[Kevin Darbyshire-Bryant]

> On 4 Mar 2019, at 21:33, Toke Høiland-Jørgensen <toke at redhat.com> wrote:
<snip>
>> I think so too though I think the mechanism of copying the DSCP bits
>> and adding a ‘I did this’ flag bit should be retained so that other
>> user space tools (iptables etc) can detect when a connmark based DSCP
>> has been set/applied.
> 
> I guess this could be an option as well?

If we don’t do that then potentially we have to look up the DSCP and update the conntrack mark for every packet.

>> I think cake ‘fwmark’ should have the smarts to look for the act_dscp
>> DSCP value if nothing else so we don’t have to have the overhead of
>> act_dscp set restoring DSCP to all the packets if we don’t want to.
> 
> Not sure what you mean here?

What I meant was that we can make the diffserv restore part optional.  Our qdisc (or whatever) could pick up the fw stored DSCP for tin/bandwidth selection and not require the real DSCP to be set and quite possibly washed/bleached again anyway.


>> I’m right at the limit of my coding ability with what I’ve sent in so
>> far - the kernel space bits of act_connmark leave me mostly confused -
>> really not sure where to start with act_dscp!
> 
> I think I would start with `cp act_connmark.c act_dscp.c`, adding the
> new file to the Makefile and Kconfig, and working from there. Then rip
> out everything not needed, and copy over what you already added to cake.
> 
> Happy to help you work out the details; but I think we'll make more
> progress on this if you are driving it :)

OK - we’ll see how long it takes before someone screams or laughs themselves to death :-)

Kevin