BUG REPORT: iproute2 seems to have bug with dsfield/tos in ip-rule and ip-route

This same problem as detailed here

http://lists.openwall.net/netdev/2010/03/26/36

or here:

https://www.spinics.net/lists/lartc/msg22541.html

bit me today

I tried either

ip rule add dsfield CS6 table 100

or

ip rule add dsfield 0xc0 table 100

or replace dsfield with tos, all return:

RTNETLINK answers: Invalid argument

on the other hand, for ip route it will accept the ds/tos values

ip route add default dsfield CS6 dev dummy0

or

ip route add default dsfield 0xc0 dev dummy0

but packets tagged with CS6 don't go to dummy0 they go the regular default route