[PATCH nf-next v2 0/2] Update (DSA) netdev stats with offloaded flows

[Ahmed Zaki <anzaki@gmail.com>]

Some devices (notably DSA) delegate the nft flowtable HW offloaded flows
to a parent drivers. The delegating drivers cannot collect or report
the offloaded flows stats since they have no access to the underlying
hardware. This breaks SNMP-based network monitoring systems that rely on
netdev stats to report the network traffic.

Fix by moving the offloaded flow stat reporting to the nft flowtable
subsystem. The first patch adds a new stats field "fstats" to net_device
that is allocated and updated by the nft subsystem only if the new
flag "flow_offload_via_parent" is set by the driver. It also report these
stats back to the user in dev_get_stats().

Patch 2 sets the new flag "flow_offload_via_parent" for the DSA driver.
---
v2: - added the new "net_device->fstats" field since the existing
      tstats cannot be used since it would double-count on devices that
      already use tstats for hardware MIBs (P1).
    - fixed the outdev ifindex logic based. See new func
      "flow_offload_egress_ifidx()" in P1.

Ahmed Zaki (2):
  netfilter: flowtable: update netdev stats with HW_OFFLOAD flows
  net: dsa: update net_device stats with HW offloaded flows stats

 include/linux/netdevice.h             | 45 ++++++++++++
 net/core/dev.c                        |  8 +++
 net/dsa/user.c                        |  1 +
 net/netfilter/nf_flow_table_offload.c | 98 +++++++++++++++++++++++++--
 4 files changed, 146 insertions(+), 6 deletions(-)

-- 
2.43.0