[dpdk-stable] [PATCH v2] net/mlx5: fix zero value validation for metadata

[Slava Ovsiienko]

> -----Original Message-----
> From: Wisam Monther <wisamm at mellanox.com>
> Sent: Thursday, March 26, 2020 12:22
> To: Ori Kam <orika at mellanox.com>; Matan Azrad <matan at mellanox.com>;
> dev at dpdk.org
> Cc: Raslan Darawsheh <rasland at mellanox.com>; Slava Ovsiienko
> <viacheslavo at mellanox.com>; stable at dpdk.org
> Subject: [PATCH v2] net/mlx5: fix zero value validation for metadata
> 
> MARK and META items are interrelated with datapath - they might move
> from/to the applications in mbuf.
> 
> zero value for these items has the special meaning - it means "no metadata
> are provided", not zero values are treated by applications and PMD as valid
> ones.
> 
> Moreover in the flow engine domain the value zero is acceptable to match
> and set, and we should allow to specify zero values as rte_flow parameters
> for the META and MARK items and actions. In the same time zero mask has
> no meaning and and should be rejected on validation stage.
> 
> Fixes: fcc8d2f716fd ("net/mlx5: extend flow metadata support")
> Fixes: e554b672aa05 ("net/mlx5: support flow tag")
> Fixes: 55deee1715f0 ("net/mlx5: extend flow mark support")
> Cc: viacheslavo at mellanox.com
> Cc: stable at dpdk.org
> 
> Signed-off-by: Wisam Jaddo <wisamm at mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo at mellanox.com>

> ---
> Changes in v2
> - Fix commit message
> - Fix documentation
> - Remove extra line
> - Always check for zero mask
> ---
> ---
>  doc/guides/nics/mlx5.rst        | 12 ++++++++++++
>  drivers/net/mlx5/mlx5_flow_dv.c | 19 +++++++++++++++----
>  2 files changed, 27 insertions(+), 4 deletions(-)
> 
> diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst index
> e8f9984df0..e13c07d9ab 100644
> --- a/doc/guides/nics/mlx5.rst
> +++ b/doc/guides/nics/mlx5.rst
> @@ -1275,6 +1275,18 @@ Supported hardware offloads
>     |                       | |  ConnectX-5   | | ConnectX-5    |
>     +-----------------------+-----------------+-----------------+
> 
> +Notes for metadata
> +------------------
> +MARK and META items are interrelated with datapath - they might move
> +from/to the applications in mbuf fields. Hence, zero value for these
> +items has the special meaning - it means "no metadata are provided",
> +not zero values are treated by applications and PMD as valid ones.
> +
> +Moreover in the flow engine domain the value zero is acceptable to
> +match and set, and we should allow to specify zero values as rte_flow
> +parameters for the META and MARK items and actions. In the same time
> +zero mask has no meaning and should be rejected on validation stage.
> +
>  Notes for testpmd
>  -----------------
> 
> diff --git a/drivers/net/mlx5/mlx5_flow_dv.c
> b/drivers/net/mlx5/mlx5_flow_dv.c index 809833b7ee..da4a925404 100644
> --- a/drivers/net/mlx5/mlx5_flow_dv.c
> +++ b/drivers/net/mlx5/mlx5_flow_dv.c
> @@ -1406,6 +1406,11 @@ flow_dv_validate_item_mark(struct rte_eth_dev
> *dev,
>  					  "mark id exceeds the limit");
>  	if (!mask)
>  		mask = &nic_mask;
> +	if (!mask->id)
> +		return rte_flow_error_set(error, EINVAL,
> +					RTE_FLOW_ERROR_TYPE_ITEM_SPEC,
> NULL,
> +					"mask cannot be zero");
> +
>  	ret = mlx5_flow_item_acceptable(item, (const uint8_t *)mask,
>  					(const uint8_t *)&nic_mask,
>  					sizeof(struct rte_flow_item_mark),
> @@ -1451,10 +1456,6 @@ flow_dv_validate_item_meta(struct rte_eth_dev
> *dev __rte_unused,
> 
> RTE_FLOW_ERROR_TYPE_ITEM_SPEC,
>  					  item->spec,
>  					  "data cannot be empty");
> -	if (!spec->data)
> -		return rte_flow_error_set(error, EINVAL,
> -
> RTE_FLOW_ERROR_TYPE_ITEM_SPEC, NULL,
> -					  "data cannot be zero");
>  	if (config->dv_xmeta_en != MLX5_XMETA_MODE_LEGACY) {
>  		if (!mlx5_flow_ext_mreg_supported(dev))
>  			return rte_flow_error_set(error, ENOTSUP, @@ -
> 1474,6 +1475,11 @@ flow_dv_validate_item_meta(struct rte_eth_dev *dev
> __rte_unused,
>  	}
>  	if (!mask)
>  		mask = &rte_flow_item_meta_mask;
> +	if (!mask->data)
> +		return rte_flow_error_set(error, EINVAL,
> +					RTE_FLOW_ERROR_TYPE_ITEM_SPEC,
> NULL,
> +					"mask cannot be zero");
> +
>  	ret = mlx5_flow_item_acceptable(item, (const uint8_t *)mask,
>  					(const uint8_t *)&nic_mask,
>  					sizeof(struct rte_flow_item_meta),
> @@ -1522,6 +1528,11 @@ flow_dv_validate_item_tag(struct rte_eth_dev
> *dev,
>  					  "data cannot be empty");
>  	if (!mask)
>  		mask = &rte_flow_item_tag_mask;
> +	if (!mask->data)
> +		return rte_flow_error_set(error, EINVAL,
> +					RTE_FLOW_ERROR_TYPE_ITEM_SPEC,
> NULL,
> +					"mask cannot be zero");
> +
>  	ret = mlx5_flow_item_acceptable(item, (const uint8_t *)mask,
>  					(const uint8_t *)&nic_mask,
>  					sizeof(struct rte_flow_item_tag),
> --
> 2.17.1