[PATCH v3 2/2] net/ice: fix scalar Tx path segment

[Mingjin Ye <mingjinx.ye@intel.com>]

The scalar Tx path would send empty buffer that causes the Tx queue to
overflow.

This patch adds the last buffer length judgment in tx_prepare to fix this
issue, rte_errno will be set to EINVAL and returned if the last buffer is
empty.

Fixes: 17c7d0f9d6a4 ("net/ice: support basic Rx/Tx")
Fixes: ccf33dccf7aa ("net/ice: check illegal packet sizes")
Cc: stable@dpdk.org

Signed-off-by: Mingjin Ye <mingjinx.ye@intel.com>
---
 drivers/net/ice/ice_rxtx.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/net/ice/ice_rxtx.c b/drivers/net/ice/ice_rxtx.c
index e6ddd2513d..69358f6a3a 100644
--- a/drivers/net/ice/ice_rxtx.c
+++ b/drivers/net/ice/ice_rxtx.c
@@ -3643,6 +3643,22 @@ ice_set_tx_function_flag(struct rte_eth_dev *dev, struct ice_tx_queue *txq)
 #define ICE_MIN_TSO_MSS            64
 #define ICE_MAX_TSO_MSS            9728
 #define ICE_MAX_TSO_FRAME_SIZE     262144
+
+/*Check for invalid mbuf*/
+static inline uint16_t
+ice_check_mbuf(struct rte_mbuf *tx_pkt)
+{
+	struct rte_mbuf *txd = tx_pkt;
+
+	while (txd != NULL) {
+		if (txd->data_len == 0)
+			return -1;
+		txd = txd->next;
+	}
+
+	return 0;
+}
+
 uint16_t
 ice_prep_pkts(__rte_unused void *tx_queue, struct rte_mbuf **tx_pkts,
 	      uint16_t nb_pkts)
@@ -3653,6 +3669,7 @@ ice_prep_pkts(__rte_unused void *tx_queue, struct rte_mbuf **tx_pkts,
 	struct ice_tx_queue *txq = tx_queue;
 	struct rte_eth_dev *dev = &rte_eth_devices[txq->port_id];
 	uint16_t max_frame_size = dev->data->mtu + ICE_ETH_OVERHEAD;
+	uint16_t nb_used;
 
 	for (i = 0; i < nb_pkts; i++) {
 		m = tx_pkts[i];
@@ -3689,6 +3706,13 @@ ice_prep_pkts(__rte_unused void *tx_queue, struct rte_mbuf **tx_pkts,
 			rte_errno = -ret;
 			return i;
 		}
+
+		if (!(ol_flags & RTE_MBUF_F_TX_TCP_SEG) &&
+			ice_check_mbuf(m)) {
+			rte_errno = EINVAL;
+			PMD_DRV_LOG(ERR, "INVALID mbuf:	last mbuf data_len=[0]");
+			return i;
+		}
 	}
 	return i;
 }
-- 
2.34.1