[PATCH v10 08/19] net/pcap: cleanup transmit buffer handling

[Stephen Hemminger]

The transmit loops should handle the possible failure
of rte_pktmbuf_read(). If a pcap_sendpacket fails, then
the packet with error should be freed.

Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
---
 drivers/net/pcap/pcap_ethdev.c | 50 ++++++++++++++--------------------
 1 file changed, 21 insertions(+), 29 deletions(-)

diff --git a/drivers/net/pcap/pcap_ethdev.c b/drivers/net/pcap/pcap_ethdev.c
index 1a186142d3..394fd0b6b2 100644
--- a/drivers/net/pcap/pcap_ethdev.c
+++ b/drivers/net/pcap/pcap_ethdev.c
@@ -389,7 +389,6 @@ static uint16_t
 eth_pcap_tx_dumper(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 {
 	unsigned int i;
-	struct rte_mbuf *mbuf;
 	struct pmd_process_private *pp;
 	struct pcap_tx_queue *dumper_q = queue;
 	uint16_t num_tx = 0;
@@ -397,7 +396,6 @@ eth_pcap_tx_dumper(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 	struct pcap_pkthdr header;
 	pcap_dumper_t *dumper;
 	unsigned char *temp_data;
-	size_t len, caplen;
 
 	pp = rte_eth_devices[dumper_q->port_id].process_private;
 	dumper = pp->tx_dumper[dumper_q->queue_id];
@@ -409,21 +407,22 @@ eth_pcap_tx_dumper(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 	/* writes the nb_pkts packets to the previously opened pcap file
 	 * dumper */
 	for (i = 0; i < nb_pkts; i++) {
-		mbuf = bufs[i];
+		struct rte_mbuf *mbuf = bufs[i];
+		uint32_t len, caplen;
+		const uint8_t *data;
+
 		len = caplen = rte_pktmbuf_pkt_len(mbuf);
 
 		calculate_timestamp(&header.ts);
 		header.len = len;
 		header.caplen = caplen;
-		/* rte_pktmbuf_read() returns a pointer to the data directly
-		 * in the mbuf (when the mbuf is contiguous) or, otherwise,
-		 * a pointer to temp_data after copying into it.
-		 */
-		pcap_dump((u_char *)dumper, &header,
-			  rte_pktmbuf_read(mbuf, 0, caplen, temp_data));
 
-		num_tx++;
-		tx_bytes += caplen;
+		data = rte_pktmbuf_read(mbuf, 0, caplen, temp_data);
+		if (likely(data != NULL)) {
+			pcap_dump((u_char *)dumper, &header, data);
+			num_tx++;
+			tx_bytes += caplen;
+		}
 	}
 	rte_pktmbuf_free_bulk(bufs, nb_pkts);
 
@@ -458,7 +457,7 @@ eth_tx_drop(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 	tx_queue->tx_stat.pkts += nb_pkts;
 	tx_queue->tx_stat.bytes += tx_bytes;
 
-	return i;
+	return nb_pkts;
 }
 
 /*
@@ -468,15 +467,12 @@ static uint16_t
 eth_pcap_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 {
 	unsigned int i;
-	int ret;
-	struct rte_mbuf *mbuf;
 	struct pmd_process_private *pp;
 	struct pcap_tx_queue *tx_queue = queue;
 	uint16_t num_tx = 0;
 	uint32_t tx_bytes = 0;
 	pcap_t *pcap;
 	unsigned char *temp_data;
-	size_t len;
 
 	pp = rte_eth_devices[tx_queue->port_id].process_private;
 	pcap = pp->tx_pcap[tx_queue->queue_id];
@@ -486,19 +482,15 @@ eth_pcap_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 		return 0;
 
 	for (i = 0; i < nb_pkts; i++) {
-		mbuf = bufs[i];
-		len = rte_pktmbuf_pkt_len(mbuf);
-
-		/* rte_pktmbuf_read() returns a pointer to the data directly
-		 * in the mbuf (when the mbuf is contiguous) or, otherwise,
-		 * a pointer to temp_data after copying into it.
-		 */
-		ret = pcap_sendpacket(pcap,
-			rte_pktmbuf_read(mbuf, 0, len, temp_data), len);
-		if (unlikely(ret != 0))
-			break;
-		num_tx++;
-		tx_bytes += len;
+		struct rte_mbuf *mbuf = bufs[i];
+		uint32_t len = rte_pktmbuf_pkt_len(mbuf);
+		const uint8_t *data;
+
+		data = rte_pktmbuf_read(mbuf, 0, len, temp_data);
+		if (likely(data != NULL && pcap_sendpacket(pcap, data, len) == 0)) {
+			num_tx++;
+			tx_bytes += len;
+		}
 	}
 
 	rte_pktmbuf_free_bulk(bufs, nb_pkts);
@@ -507,7 +499,7 @@ eth_pcap_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 	tx_queue->tx_stat.bytes += tx_bytes;
 	tx_queue->tx_stat.err_pkts += i - num_tx;
 
-	return i;
+	return nb_pkts;
 }
 
 /*
-- 
2.51.0