On 9/28/17 2:23 PM, John Fastabend wrote: > [...] > >> I'm pretty sure I misunderstood what you were going after with >> XDP_REDIRECT reserving the headroom. Our use case (patches coming in a >> few weeks) will populate the headroom coming out of the driver to XDP, >> and then once the XDP program extracts whatever hints it wants via >> helpers, I fully expect that area in the headroom to get stomped by >> something else. If we want to send any of that hint data up farther, >> we'll already have it extracted via the helpers, and the eBPF program >> can happily assign it to wherever in the outbound metadata area. > > In case its not obvious with the latest xdp metadata patches the outbound > metadata can then be pushed into skb fields via a tc_cls program if needed.
Yes, that was what I was alluding to with "can happily assign it to wherever." The patches we're working on are driver->XDP, then anything else using the latest meta-data patches would be XDP->anywhere else. So I don't think we're going to step on any toes. Thanks John, -PJ
