From: =?UTF-8?q?Ond=C5=99ej=20Hlavat=C3=BD?= <ohlavaty@redhat.com>
Date: Thu, 31 May 2018 23:21:04 +0200
Subject: ixgbe: fix parsing of TC actions for HW offload
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Patch-mainline: v4.17
Git-commit: 16e6653c8259ca5383126e1c6bcf7fe062af87fc
References: bsc#1113994 FATE#326315 FATE#326317

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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

--- 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
 {
 	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
 
 			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;