Re: [dpdk-stable] [dpdk-dev] [PATCH] net/mlx5: fix GRE flow rule

[Matan Azrad <matan@mellanox.com>]

Hi Yongseok

From:  Yongseok Koh
> Creating a flow having pattern from the middle of a packet is allowed. For
> example,
> 
>   testpmd> flow create 0 ingress pattern vxlan vni is 20 / end actions ...
> 
> Device can parse GRE header but without proper support from library and
> firmware (HAVE_IBV_DEVICE_MPLS_SUPPORT), a field in GRE header can't be
> specified when creating a rule. As a result, the following rule will be
> interpreted as a wildcard rule, which always matches any packet.
> 
>   testpmd> flow create 0 ingress pattern gre / end actions ...
> Fixes: 96c6c65a10d2 ("net/mlx5: support GRE tunnel flow")
> Fixes: 1f106da2bf7b ("net/mlx5: support MPLS-in-GRE and MPLS-in-UDP")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
> ---
>  drivers/net/mlx5/mlx5_flow.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c index
> 994be05be..526fe6b0e 100644
> --- a/drivers/net/mlx5/mlx5_flow.c
> +++ b/drivers/net/mlx5/mlx5_flow.c
> @@ -330,9 +330,11 @@ static const enum rte_flow_action_type
> valid_actions[] = {  static const struct mlx5_flow_items mlx5_flow_items[] = {
>  	[RTE_FLOW_ITEM_TYPE_END] = {
>  		.items = ITEMS(RTE_FLOW_ITEM_TYPE_ETH,
> +#ifdef HAVE_IBV_DEVICE_MPLS_SUPPORT

The GRE item was here even before the MPLSoGRE support so I think that this is not the correct fix and even that it can hurt the support of GRE for the current customers use it.

Looks like you must specify at least 1 spec in the GRE to apply it correctly as you did for VXLAN,
Can you try empty vxlan and fully gre (with protocol field)?

> +			       RTE_FLOW_ITEM_TYPE_GRE,
> +#endif
>  			       RTE_FLOW_ITEM_TYPE_VXLAN,
> -			       RTE_FLOW_ITEM_TYPE_VXLAN_GPE,
> -			       RTE_FLOW_ITEM_TYPE_GRE),
> +			       RTE_FLOW_ITEM_TYPE_VXLAN_GPE),
>  	},
>  	[RTE_FLOW_ITEM_TYPE_ETH] = {
>  		.items = ITEMS(RTE_FLOW_ITEM_TYPE_VLAN,