[dpdk-dev] [PATCH 7/9] net/hns3: fix missing length of hash key when getting RSS

["Wei Hu (Xavier)" <huwei013@chinasoftinc.com>]

From: Lijun Ou <oulijun@huawei.com>

When upper application calls the rte_eth_dev_rss_hash_conf_get API
function to get the RSS key parameters, the function should return the
RSS key length supported by the device. Otherwise, an error will occur
when the upper application needs to use the RSS key length supported
by this specified hardware for judgment and configure the specified
key into hardware.

For example, in the following scenario:
When users want to use their own RSS key, but the length of the key is
bigger than the one of the supported by hardware.

As a result, users need to get the RSS key length supported by hardware
according to the above API firstly, and then compare the actual obtained
RSS key length with the length of their own RSS key.

If the drvier does not return the actual value, error may coccur when user
calls the rte_eth_dev_rss_hash_update API function to configure their own
kye into hardware.

Besides, this patch fixes the problem of stepping on memory when the RSS
key array configured by users are less than the RSS key length supported
by the driver at the same time.

Fixes: c37ca66f2b27 ("net/hns3: support RSS")
Cc: stable@dpdk.org

Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Signed-off-by: Chengchang Tang <tangchengchang@huawei.com>
---
 drivers/net/hns3/hns3_rss.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/hns3/hns3_rss.c b/drivers/net/hns3/hns3_rss.c
index 95a637ddc..a6cab29c9 100644
--- a/drivers/net/hns3/hns3_rss.c
+++ b/drivers/net/hns3/hns3_rss.c
@@ -328,8 +328,10 @@ hns3_dev_rss_hash_conf_get(struct rte_eth_dev *dev,
 	rss_conf->rss_hf = rss_cfg->conf.types;
 
 	/* Get the RSS Key required by the user */
-	if (rss_conf->rss_key)
+	if (rss_conf->rss_key && rss_conf->rss_key_len >= HNS3_RSS_KEY_SIZE) {
 		memcpy(rss_conf->rss_key, rss_cfg->key, HNS3_RSS_KEY_SIZE);
+		rss_conf->rss_key_len = HNS3_RSS_KEY_SIZE;
+	}
 	rte_spinlock_unlock(&hw->lock);
 
 	return 0;
-- 
2.23.0