net/mlx5: fix flows when VXLAN tunnel is 0

Fix a strange behavior from the NIC, when the flow starts with a VXLAN
layer with a VNI equals to zero all the traffic will match within this
rule.

Fixes: 2e709b6aa0f5 ("net/mlx5: support VXLAN flow item")
Cc: stable@dpdk.org
Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
Acked-by: Yongseok Koh <yskoh@mellanox.com>

diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index cdb880a..19da9f1 100644 (file)
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -129,6 +129,8 @@ Limitations
   is set to multi-packet send or Enhanced multi-packet send. Otherwise it must have
   less than 50 segments.
 - Count action for RTE flow is only supported in Mellanox OFED 4.2.
+- Flows with a VXLAN Network Identifier equal (or ends to be equal)
+  to 0 are not supported.
 
 Configuration
 -------------

diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
index f4bdf2c..c281e40 100644 (file)
--- a/drivers/net/mlx5/mlx5_flow.c
+++ b/drivers/net/mlx5/mlx5_flow.c
@@ -1155,7 +1155,7 @@ priv_flow_convert(struct priv *priv,
                                         cur_item->mask),
                                        parser);
                if (ret) {
-                       rte_flow_error_set(error, ENOTSUP,
+                       rte_flow_error_set(error, ret,
                                           RTE_FLOW_ERROR_TYPE_ITEM,
                                           items, "item not supported");
                        goto exit_free;
@@ -1602,6 +1602,16 @@ mlx5_flow_create_vxlan(const struct rte_flow_item *item,
                /* Remove unwanted bits from values. */
                vxlan.val.tunnel_id &= vxlan.mask.tunnel_id;
        }
+       /*
+        * Tunnel id 0 is equivalent as not adding a VXLAN layer, if only this
+        * layer is defined in the Verbs specification it is interpreted as
+        * wildcard and all packets will match this rule, if it follows a full
+        * stack layer (ex: eth / ipv4 / udp), all packets matching the layers
+        * before will also match this rule.
+        * To avoid such situation, VNI 0 is currently refused.
+        */
+       if (!vxlan.val.tunnel_id)
+               return EINVAL;
        mlx5_flow_create_copy(parser, &vxlan, size);
        return 0;
 }