[PATCH] net/pcap: use pcap_next_ex to track errors

[Stephen Hemminger]

Use pcap_next_ex rather than just pcap_next because pcap_next
always blocks if there is no packets to receive.

Bugzilla ID: 1526
Reported-by: Ofer Dagan <ofe...@claroty.com>
Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
---
 drivers/net/pcap/pcap_ethdev.c | 33 +++++++++++++++++----------------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/net/pcap/pcap_ethdev.c b/drivers/net/pcap/pcap_ethdev.c
index bfec085045..261997be5c 100644
--- a/drivers/net/pcap/pcap_ethdev.c
+++ b/drivers/net/pcap/pcap_ethdev.c
@@ -274,7 +274,7 @@ static uint16_t
 eth_pcap_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 {
        unsigned int i;
-       struct pcap_pkthdr header;
+       struct pcap_pkthdr *header;
        struct pmd_process_private *pp;
        const u_char *packet;
        struct rte_mbuf *mbuf;
@@ -294,9 +294,13 @@ eth_pcap_rx(void *queue, struct rte_mbuf **bufs, uint16_t 
nb_pkts)
         */
        for (i = 0; i < nb_pkts; i++) {
                /* Get the next PCAP packet */
-               packet = pcap_next(pcap, &header);
-               if (unlikely(packet == NULL))
+               int ret = pcap_next_ex(pcap, &header, &packet);
+               if (ret != 1) {
+                       if (ret == PCAP_ERROR)
+                               pcap_q->rx_stat.err_pkts++;
+
                        break;
+               }
 
                mbuf = rte_pktmbuf_alloc(pcap_q->mb_pool);
                if (unlikely(mbuf == NULL)) {
@@ -304,33 +308,30 @@ eth_pcap_rx(void *queue, struct rte_mbuf **bufs, uint16_t 
nb_pkts)
                        break;
                }
 
-               if (header.caplen <= rte_pktmbuf_tailroom(mbuf)) {
+               uint32_t len = header->caplen;
+               if (len <= rte_pktmbuf_tailroom(mbuf)) {
                        /* pcap packet will fit in the mbuf, can copy it */
-                       rte_memcpy(rte_pktmbuf_mtod(mbuf, void *), packet,
-                                       header.caplen);
-                       mbuf->data_len = (uint16_t)header.caplen;
+                       rte_memcpy(rte_pktmbuf_mtod(mbuf, void *), packet, len);
+                       mbuf->data_len = len;
                } else {
                        /* Try read jumbo frame into multi mbufs. */
                        if (unlikely(eth_pcap_rx_jumbo(pcap_q->mb_pool,
-                                                      mbuf,
-                                                      packet,
-                                                      header.caplen) == -1)) {
+                                                      mbuf, packet, len) == 
-1)) {
                                pcap_q->rx_stat.err_pkts++;
                                rte_pktmbuf_free(mbuf);
                                break;
                        }
                }
 
-               mbuf->pkt_len = (uint16_t)header.caplen;
-               *RTE_MBUF_DYNFIELD(mbuf, timestamp_dynfield_offset,
-                       rte_mbuf_timestamp_t *) =
-                               (uint64_t)header.ts.tv_sec * 1000000 +
-                               header.ts.tv_usec;
+               mbuf->pkt_len = len;
+               uint64_t us = (uint64_t)header->ts.tv_sec * US_PER_S + 
header->ts.tv_usec;
+
+               *RTE_MBUF_DYNFIELD(mbuf, timestamp_dynfield_offset, 
rte_mbuf_timestamp_t *) = us;
                mbuf->ol_flags |= timestamp_rx_dynflag;
                mbuf->port = pcap_q->port_id;
                bufs[num_rx] = mbuf;
                num_rx++;
-               rx_bytes += header.caplen;
+               rx_bytes += len;
        }
        pcap_q->rx_stat.pkts += num_rx;
        pcap_q->rx_stat.bytes += rx_bytes;
-- 
2.45.2