On Thu, Jan 29, 2026 at 4:23 PM Joe Damato [off-list ref] wrote:

It appears that in commit 7efd79c0e689 ("bnxt_en: Add drop action
support for ntuple"), bnxt gained support for ntuple filters for packet
drops.

However, support for this does not seem to work in recent kernels or
against net-next:

  % sudo ethtool -U eth0 flow-type udp4 src-ip 1.1.1.1 action -1
    rmgr: Cannot insert RX class rule: Operation not supported
    Cannot insert classification rule

The issue is that the existing code uses ethtool_get_flow_spec_ring_vf,
which will return a non-zero value if the ring_cookie is set to
RX_CLS_FLOW_DISC, which then causes bnxt_add_ntuple_cls_rule to return
-EOPNOTSUPP because it thinks the user is trying to set an ntuple filter
for a vf.

Fix this by first checking that the ring_cookie is not RX_CLS_FLOW_DISC.

After this patch, ntuple filters for drops can be added:

  % sudo ethtool -U eth0 flow-type udp4 src-ip 1.1.1.1 action -1
  Added rule with ID 0

  % ethtool -n eth0
  44 RX rings available
  Total 1 rules

  Filter: 0
      Rule Type: UDP over IPv4
      Src IP addr: 1.1.1.1 mask: 0.0.0.0
      Dest IP addr: 0.0.0.0 mask: 255.255.255.255
      TOS: 0x0 mask: 0xff
      Src port: 0 mask: 0xffff
      Dest port: 0 mask: 0xffff
      Action: Drop

Signed-off-by: Joe Damato <redacted>
---
v2:
  - Extract the FLOW_MAC_EXT and FLOW_EXT check so it happens unconditionally.
  - Eliminate the local variable ring, which was used in only one place and
    call ethtool_get_flow_spec_ring instead.

v1: https://lore.kernel.org/netdev/20260128222718.1679581-1-joe@dama.to/ (local)

One minor improvement is to eliminate the vf variable since it is also
used only once.  But I'm fine with this patch.  Thanks.

Reviewed-by: Michael Chan <michael.chan@broadcom.com>