Hi Jakub, Please see my responses inline: On Fri, 13 Nov 2020 15:54:37 -0800 Jakub Kicinski <kuba@xxxxxxxxxx> wrote: > On Sat, 14 Nov 2020 00:00:24 +0100 Andrea Mayer wrote: > > On Fri, 13 Nov 2020 13:40:10 -0800 > > Jakub Kicinski <kuba@xxxxxxxxxx> wrote: > > > > I can tackle the v6 version but how do we face the compatibility issue raised > > by Stefano in his message? > > > > if it is ok to implement a uAPI that breaks the existing scripts, it is relatively > > easy to replicate the VRF-based approach also in v6. > > We need to keep existing End.DT6 as is, and add a separate > implementation. ok > > The way to distinguish between the two could be either by > 1) passing via > netlink a flag attribute (which would request use of VRF in both > cases); yes, feasible... see UAPI solution 1 > 2) using a different attribute than SEG6_LOCAL_TABLE for the > table id (or perhaps passing VRF's ifindex instead), e.g. > SEG6_LOCAL_TABLE_VRF; yes, feasible... see UAPI solution 2 > 3) or adding a new command > (SEG6_LOCAL_ACTION_END_DT6_VRF) which would behave like End.DT4. no, we prefer not to add a new command, because it is better to keep a semantic one-to-one relationship between these commands and the SRv6 behaviors defined in the draft. UAPI solution 1 we add a new parameter "vrfmode". DT4 can only be used with the vrfmode parameter (hence it is a required parameter for DT4). DT6 can be used with "vrfmode" (new vrf based mode) or without "vrfmode" (legacy mode)(hence "vrfmode" is an optional parameter for DT6) UAPI solution 1 examples: ip -6 route add 2001:db8::1/128 encap seg6local action End.DT4 vrfmode table 100 dev eth0 ip -6 route add 2001:db8::1/128 encap seg6local action End.DT6 vrfmode table 100 dev eth0 ip -6 route add 2001:db8::1/128 encap seg6local action End.DT6 table 100 dev eth0 UAPI solution 2 we turn "table" into an optional parameter and we add the "vrftable" optional parameter. DT4 can only be used with the "vrftable" (hence it is a required parameter for DT4). DT6 can be used with "vrftable" (new vrf mode) or with "table" (legacy mode) (hence it is an optional parameter for DT6). UAPI solution 2 examples: ip -6 route add 2001:db8::1/128 encap seg6local action End.DT4 vrftable 100 dev eth0 ip -6 route add 2001:db8::1/128 encap seg6local action End.DT6 vrftable 100 dev eth0 ip -6 route add 2001:db8::1/128 encap seg6local action End.DT6 table 100 dev eth0 IMO solution 2 is nicer from UAPI POV because we always have only one parameter, maybe solution 1 is slightly easier to implement, all in all we prefer solution 2 but we can go for 1 if you prefer. Waiting for your advice! Thanks, Andrea
