From: Jeff Kirsher <redacted>
Date: Wed, 30 May 2018 11:01:34 -0700

From: Ondřej Hlavatý <redacted>

The previous code was optimistic, accepting the offload of whole action
chain when there was a single known action (drop/redirect). This results
in offloading a rule which should not be offloaded, because its behavior
cannot be reproduced in the hardware.

For example:

$ tc filter add dev eno1 parent ffff: protocol ip \
    u32 ht 800: order 1 match tcp src 42 FFFF \
    action mirred egress mirror dev enp1s16 pipe \
    drop

The controller is unable to mirror the packet to a VF, but still
offloads the rule by dropping the packet.

Change the approach of the function to a pessimistic one, rejecting the
chain when an unknown action is found. This is better suited for future
extensions.

Note that both recognized actions always return TC_ACT_SHOT, therefore
it is safe to ignore actions behind them.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Ondřej Hlavatý <redacted>
Tested-by: Andrew Bowers <redacted>
Signed-off-by: Jeff Kirsher <redacted>

This introduces a new warning with gcc-8.1.1 on Fedora 28.

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c: In function ‘ixgbe_configure_clsu32’:
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c:9311:8: warning: ‘queue’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  err = ixgbe_fdir_write_perfect_filter_82599(hw, &input->filter,
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           input->sw_idx, queue);
           ~~~~~~~~~~~~~~~~~~~~~