[PATCH] net/nfp: add the restrict of setting the mtu

[PATCH] net/nfp: add the restrict of setting the mtu

[Peng Zhang]

1.When the setting mtu is higher than flbufsz, the mtu doesn't work.
But it doesn't have any notice about this restrict.
2.when the setting mtu isn't in the range, it doesn't have any notice.

This patch will add the notice about these restrict.

Signed-off-by: Peng Zhang <peng.zhang@corigine.com>
Signed-off-by: Chaoyong He <chaoyong.he@corigine.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
---
 drivers/net/nfp/nfp_common.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/net/nfp/nfp_common.c b/drivers/net/nfp/nfp_common.c
index f8978e803a..2ea9853548 100644
--- a/drivers/net/nfp/nfp_common.c
+++ b/drivers/net/nfp/nfp_common.c
@@ -956,6 +956,20 @@ nfp_net_dev_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
 		return -EBUSY;
 	}
 
+	/* the setting mtu is in the range */
+	if (mtu < 68 || mtu > hw->max_mtu) {
+		PMD_DRV_LOG(ERR, "the setting mtu cannot be less than 68 or more than %d",
+			    hw->max_mtu);
+		return -ERANGE;
+	}
+
+	/* the setting mtu is lower than flbufsz */
+	if (mtu > hw->flbufsz) {
+		PMD_DRV_LOG(ERR, "the setting mtu must be lower than current mbufsize of %d",
+			    hw->flbufsz);
+		return -ERANGE;
+	}
+
 	/* writing to configuration space */
 	nn_cfg_writel(hw, NFP_NET_CFG_MTU, mtu);
 
-- 
2.27.0

Re: [PATCH] net/nfp: add the restrict of setting the mtu

[Stephen Hemminger]

On Thu, 17 Mar 2022 16:39:17 +0200
Peng Zhang <peng.zhang@corigine.com> wrote:

> +	/* the setting mtu is in the range */
> +	if (mtu < 68 || mtu > hw->max_mtu) {
> +		PMD_DRV_LOG(ERR, "the setting mtu cannot be less than 68 or more than %d",
> +			    hw->max_mtu);
> +		return -ERANGE;
> +	}
> +
> +	/* the setting mtu is lower than flbufsz */
> +	if (mtu > hw->flbufsz) {
> +		PMD_DRV_LOG(ERR, "the setting mtu must be lower than current mbufsize of %d",
> +			    hw->flbufsz);
> +		return -ERANGE;

The ethdev layer already has min/max mtu checks, why is it needed inside common code?

It looks like nfp_net_infos_get() does not set these values.
Please fix it there instead.

PS: 68 is RTE_ETHER_MIN_MTU so please use that.

[PATCH] net/nfp: add the restrict of setting the mtu

[Peng Zhang]

1.When the setting mtu is higher than flbufsz, the mtu doesn't work.
But it doesn't have any notice about this restrict.
2.when the setting mtu isn't in the range, it doesn't have any notice.

This patch will add the notice about these restrict.

Signed-off-by: Peng Zhang <peng.zhang@corigine.com>
Signed-off-by: Chaoyong He <chaoyong.he@corigine.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
---
 drivers/net/nfp/nfp_common.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/net/nfp/nfp_common.c b/drivers/net/nfp/nfp_common.c
index f8978e803a..2ea9853548 100644
--- a/drivers/net/nfp/nfp_common.c
+++ b/drivers/net/nfp/nfp_common.c
@@ -956,6 +956,20 @@ nfp_net_dev_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
 		return -EBUSY;
 	}
 
+	/* the setting mtu is in the range */
+	if (mtu < 68 || mtu > hw->max_mtu) {
+		PMD_DRV_LOG(ERR, "the setting mtu cannot be less than 68 or more than %d",
+			    hw->max_mtu);
+		return -ERANGE;
+	}
+
+	/* the setting mtu is lower than flbufsz */
+	if (mtu > hw->flbufsz) {
+		PMD_DRV_LOG(ERR, "the setting mtu must be lower than current mbufsize of %d",
+			    hw->flbufsz);
+		return -ERANGE;
+	}
+
 	/* writing to configuration space */
 	nn_cfg_writel(hw, NFP_NET_CFG_MTU, mtu);
 
-- 
2.27.0