ixgbe: fix parsing of TC actions for HW offload

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.

Signed-off-by: Ondřej Hlavatý <ohlavaty@redhat.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 5 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index afadba99f7b8..2ecd55856c50 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -9054,7 +9054,6 @@ static int parse_tc_actions(struct ixgbe_adapter *adapter,
 {
         const struct tc_action *a;
         LIST_HEAD(actions);
-        int err;
 
         if (!tcf_exts_has_actions(exts))
                 return -EINVAL;
@@ -9075,11 +9074,11 @@ static int parse_tc_actions(struct ixgbe_adapter *adapter,
 
                         if (!dev)
                                 return -EINVAL;
-                        err = handle_redirect_action(adapter, dev->ifindex, queue,
-                                                     action);
-                        if (err == 0)
-                                return err;
+                        return handle_redirect_action(adapter, dev->ifindex,
+                                                      queue, action);
                 }
+
+                return -EINVAL;
         }
 
         return -EINVAL;