[PATCH v3 3/3] net/txgbe: fix FDIR error handling on flow create

[Zhang Tengfei <zhtfdev@gmail.com>]

On failure, txgbe_flow_create() calls rte_flow_error_set(error, -ret),
so ret must be a negative errno. The FDIR flex offset mismatch path
leaves ret at 0, and the application sees errno 0. The global mask
memcmp path stores memcmp's return value in ret, which is not an
errno. Set -EINVAL on both paths.

Reject a mask-only FDIR rule before programming the global input mask,
so a failed create cannot leave the mask committed.

Fixes: 5c2352b9ece6 ("net/txgbe: support creating consistent filter")
Cc: stable@dpdk.org

Signed-off-by: Zhang Tengfei <zhtfdev@gmail.com>
---
 drivers/net/txgbe/txgbe_flow.c | 56 ++++++++++++++++++----------------
 1 file changed, 30 insertions(+), 26 deletions(-)

diff --git a/drivers/net/txgbe/txgbe_flow.c b/drivers/net/txgbe/txgbe_flow.c
index a1a497fa22..b4138cdc4e 100644
--- a/drivers/net/txgbe/txgbe_flow.c
+++ b/drivers/net/txgbe/txgbe_flow.c
@@ -3355,6 +3355,12 @@ txgbe_flow_create(struct rte_eth_dev *dev,
 			goto out;
 		}
 
+		if (!fdir_rule.b_spec) {
+			rte_free(fdir_rule_ptr);
+			ret = -EINVAL;
+			goto out;
+		}
+
 		/* A mask cannot be deleted. */
 		if (fdir_rule.b_mask) {
 			if (!fdir_info->mask_added) {
@@ -3388,12 +3394,12 @@ txgbe_flow_create(struct rte_eth_dev *dev,
 				 * Only support one global mask,
 				 * all the masks should be the same.
 				 */
-				ret = memcmp(&fdir_info->mask,
+				if (memcmp(&fdir_info->mask,
 					&fdir_rule.mask,
-					sizeof(struct txgbe_hw_fdir_mask));
-				if (ret) {
+					sizeof(struct txgbe_hw_fdir_mask)) != 0) {
 					PMD_DRV_LOG(ERR, "only support one global mask");
 					rte_free(fdir_rule_ptr);
+					ret = -EINVAL;
 					goto out;
 				}
 
@@ -3401,37 +3407,35 @@ txgbe_flow_create(struct rte_eth_dev *dev,
 				    fdir_rule.flex_bytes_offset ||
 				    fdir_info->flex_relative !=
 				    fdir_rule.flex_relative) {
+					PMD_DRV_LOG(ERR,
+						"flex bytes offset mismatch");
 					rte_free(fdir_rule_ptr);
+					ret = -EINVAL;
 					goto out;
 				}
 			}
 		}
 
-		if (fdir_rule.b_spec) {
-			ret = txgbe_fdir_filter_program(dev, &fdir_rule,
-					FALSE, FALSE);
-			if (ret) {
-				rte_free(fdir_rule_ptr);
-				/**
-				 * clean the mask_added flag if fail to
-				 * program
-				 **/
-				if (first_mask)
-					fdir_info->mask_added = FALSE;
-				goto out;
-			}
-
-			fdir_rule_ptr->filter_info = fdir_rule;
-			TAILQ_INSERT_TAIL(&filter_fdir_list,
-				fdir_rule_ptr, entries);
-			flow->rule = fdir_rule_ptr;
-			flow->filter_type = RTE_ETH_FILTER_FDIR;
-
-			return flow;
+		ret = txgbe_fdir_filter_program(dev, &fdir_rule,
+				FALSE, FALSE);
+		if (ret) {
+			rte_free(fdir_rule_ptr);
+			/**
+			 * clean the mask_added flag if fail to
+			 * program
+			 **/
+			if (first_mask)
+				fdir_info->mask_added = FALSE;
+			goto out;
 		}
 
-		rte_free(fdir_rule_ptr);
-		goto out;
+		fdir_rule_ptr->filter_info = fdir_rule;
+		TAILQ_INSERT_TAIL(&filter_fdir_list,
+			fdir_rule_ptr, entries);
+		flow->rule = fdir_rule_ptr;
+		flow->filter_type = RTE_ETH_FILTER_FDIR;
+
+		return flow;
 	}
 
 	memset(&l2_tn_filter, 0, sizeof(struct txgbe_l2_tunnel_conf));
-- 
2.53.0