[Cake] flow dissector idea/enhancement - help

[Jonathan Morton]

> On 2 Jun, 2016, at 14:09, Kevin Darbyshire-Bryant <kevin at darbyshire-bryant.me.uk> wrote:
> 
> Cake uses the flow dissector API to do flow hashing...including per host flows for dual/triple isolation.  The unfortunate bit is that the qdisc inevitably gets placed after packets have been NATed on egress and before they've been de-NATed on ingress.
> 
> When mentioned before Johnathan said "flow dissector ideally needs to be tweaked to do this" or words to that effect.
> 
> I'd like to progress that idea...the thought of me kernel programming should horrify everyone but really I'm asking for help in being pointed in the right direction to ask for help...and go from there :-)

I believe Linux does NAT using a “connection tracker” subsystem.  That would contain the necessary data for resolving NAT equivalents.  I don’t know how easy it is to query in a qdisc context, though.

 - Jonathan Morton