From: Ajit Khaparde <ajit.khaparde@broadcom.com>
Date: Wed, 15 May 2019 18:08:14 +0000 (-0700)
Subject: net/bnxt: check for error conditions in Tx path
X-Git-Url: http://git.droids-corp.org/?p=dpdk.git;a=commitdiff_plain;h=77942f509b09c934320e1226d82797b3c80eb968

net/bnxt: check for error conditions in Tx path

The HW can have limits on the minimum packet size it can support,
or the maximum number of segments it can support. Check for such
possibilities. Also check if we are going to have a 0 length buffer.

Fixes: 6eb3cc2294fd ("net/bnxt: add initial Tx code")
Cc: stable@dpdk.org

Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
---

diff --git a/drivers/net/bnxt/bnxt_txr.c b/drivers/net/bnxt/bnxt_txr.c
index 3a0d73af20..9684fb1775 100644
--- a/drivers/net/bnxt/bnxt_txr.c
+++ b/drivers/net/bnxt/bnxt_txr.c
@@ -143,6 +143,33 @@ static uint16_t bnxt_start_xmit(struct rte_mbuf *tx_pkt,
 	tx_buf->mbuf = tx_pkt;
 	tx_buf->nr_bds = long_bd + tx_pkt->nb_segs;
 
+	/* Check if number of Tx descriptors is above HW limit */
+	if (unlikely(tx_buf->nr_bds > BNXT_MAX_TSO_SEGS)) {
+		PMD_DRV_LOG(ERR,
+			    "Num descriptors %d exceeds HW limit\n",
+			    tx_buf->nr_bds);
+		return -ENOSPC;
+	}
+
+	/* If packet length is less than minimum packet size, pad it */
+	if (unlikely(rte_pktmbuf_pkt_len(tx_pkt) < BNXT_MIN_PKT_SIZE)) {
+		uint8_t pad = BNXT_MIN_PKT_SIZE - rte_pktmbuf_pkt_len(tx_pkt);
+		char *seg = rte_pktmbuf_append(tx_pkt, pad);
+
+		if (!seg) {
+			PMD_DRV_LOG(ERR,
+				    "Failed to pad mbuf by %d bytes\n",
+				    pad);
+			return -ENOMEM;
+		}
+
+		/* Note: data_len, pkt len are updated in rte_pktmbuf_append */
+		memset(seg, 0, pad);
+	}
+
+	/* Check non zero data_len */
+	RTE_VERIFY(tx_pkt->data_len);
+
 	if (unlikely(bnxt_tx_avail(txr) < tx_buf->nr_bds))
 		return -ENOMEM;
 
@@ -203,6 +230,7 @@ static uint16_t bnxt_start_xmit(struct rte_mbuf *tx_pkt,
 			 */
 			txbd1->hdr_size = hdr_size >> 1;
 			txbd1->mss = tx_pkt->tso_segsz;
+			RTE_VERIFY(txbd1->mss);
 
 		} else if ((tx_pkt->ol_flags & PKT_TX_OIP_IIP_TCP_UDP_CKSUM) ==
 			   PKT_TX_OIP_IIP_TCP_UDP_CKSUM) {
@@ -285,8 +313,9 @@ static uint16_t bnxt_start_xmit(struct rte_mbuf *tx_pkt,
 	}
 
 	m_seg = tx_pkt->next;
-	/* i is set at the end of the if(long_bd) block */
 	while (m_seg) {
+		/* Check non zero data_len */
+		RTE_VERIFY(m_seg->data_len);
 		txr->tx_prod = RING_NEXT(txr->tx_ring_struct, txr->tx_prod);
 		tx_buf = &txr->tx_buf_ring[txr->tx_prod];
 
diff --git a/drivers/net/bnxt/bnxt_txr.h b/drivers/net/bnxt/bnxt_txr.h
index 7f3c7cdb04..f802d5080d 100644
--- a/drivers/net/bnxt/bnxt_txr.h
+++ b/drivers/net/bnxt/bnxt_txr.h
@@ -10,6 +10,8 @@
 
 #define MAX_TX_RINGS	16
 #define BNXT_TX_PUSH_THRESH 92
+#define BNXT_MAX_TSO_SEGS	32
+#define BNXT_MIN_PKT_SIZE	52
 
 #define B_TX_DB(db, prod)	rte_write32((DB_KEY_TX | (prod)), db)