On Sat, Jan 6, 2018 at 10:57 AM, Pravin Shelar <pshe...@ovn.org> wrote: > On Fri, Jan 5, 2018 at 10:59 PM, Ed Swierk <eswi...@skyportsystems.com> wrote: >> >> >> On Jan 5, 2018 22:17, "Pravin Shelar" <pshe...@ovn.org> wrote: >> >> On Fri, Jan 5, 2018 at 3:20 PM, Ed Swierk <eswi...@skyportsystems.com> >> wrote: >>> On Fri, Jan 5, 2018 at 10:14 AM, Ed Swierk <eswi...@skyportsystems.com> >>> wrote: >>>> On Thu, Jan 4, 2018 at 7:36 PM, Pravin Shelar <pshe...@ovn.org> wrote: >>>>> OVS already pull all required headers in skb linear data, so no need >>>>> to redo all of it. only check required is the ip-checksum validation. >>>>> I think we could avoid it in most of cases by checking skb length to >>>>> ipheader length before verifying the ip header-checksum. >>>> >>>> Shouldn't the IP header checksum be verified even earlier, like in >>>> key_extract(), before actually using any of the fields in the IP >>>> header? >>> >>> Something like this for verifying the IP header checksum (not tested): >>> >> AFAIU openflow does not need this verification, so it is not required >> in flow extract. >> >> >> Okay. How about my proposed trimming implementation, caching the pad length >> in the ovs cb? >> > Caching the length is not that simple, OVS actions can change the > length. Keeping it consistent with packet would be more work, so lets > calculate it in ovs-ct function.
You could make it specific for skb-len-trimming, something like boolean flag. so that it is easy to reason with.
