On Sat, May 27, 2017 at 8:18 PM, Tom Herbert <t...@herbertland.com> wrote:
> I think the problem is I don't know what you're dealing with. The only > thing I can derive from the commit log is that tos and ttl are being > extracted, but I don't know why they are needed. The current case for matching on TTL I am dealing with is for using TC/flower for offloading OVS in flow based VM traffic routing env (Open-Stack and ODL DVR - Distributed Virtual Routing) -- where packet headers are re-written to set the next hop MACs and the TTL is changed. Fields which are modified are also matched beforhand, and here comes the matching on TTL. > I do know this is > adding complexity to an already overly complex function, and this > introduces new conditionals and code into the primary use case of > flow_dissector which is to create a key for deriving skb->hash. I > don't see that the cost of this patch has been justified. I hear what you're saying, but part of the rules is that everything to be offloaded can also be carried out in the kernel SW data-path, so here comes the touching that area. I have used the minimal foot print I could and set the code to run in a separate helper called from the main dissection function. >> When we did the the flower patches for being able to classify on both >> the inner and outer fields (say outer src/dst ip, tunnel key) for what >> related to the macs/ips/ports/etc -- I don't think we touched the >> existing dissection, I will look on that to see if I am wrong..
