TC stats / hw offload question

Edward Cree
2019-02-05T19:41:26Z

Regarding TC_CLSFLOWER_STATS, when a filter rule modifies the length of
the packet, e.g. by adding a VLAN or encap header, should the bytes
counter count the length of the packet _before_ edits (i.e. as seen by
the match), or the length after edits?  If the latter, what is the
correct behaviour when (say) a packet is mirrored as-is but also
redirected with encapsulation?
The fact that the stats live in the struct tc_action suggests a per-
action connection that would imply post-edit length, but then in
tcf_exts_dump_stats() we only look at the first action, which seems to
imply we really want the pre-edit length.
I can't find any kind of doc or spec defining what behaviour is required.

-Ed