[dpdk-dev] [PATCH] pmd_pcap: fixed incorrect mbuf allocation

["Richardson, Bruce" <bruce.richardson@intel.com>]

The mbufs returned by the pcap pmd RX function were constantly
reused, instead of being allocated on demand. This has been fixed.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
lib/librte_pmd_pcap/rte_eth_pcap.c |   37 +++++++++++++++++++++++++----------
1 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/lib/librte_pmd_pcap/rte_eth_pcap.c b/lib/librte_pmd_pcap/rte_eth_pcap.c
index 19d19b3..8a98471 100644
--- a/lib/librte_pmd_pcap/rte_eth_pcap.c
+++ b/lib/librte_pmd_pcap/rte_eth_pcap.c
@@ -118,32 +118,47 @@ eth_pcap_rx(void *queue,
        struct pcap_pkthdr header;
        const u_char *packet;
        struct rte_mbuf *mbuf;
-       static struct rte_mbuf *mbufs[RTE_ETH_PCAP_MBUFS] = { 0 };
        struct pcap_rx_queue *pcap_q = queue;
+       struct rte_pktmbuf_pool_private *mbp_priv;
        uint16_t num_rx = 0;
+       uint16_t buf_size;

        if (unlikely(pcap_q->pcap == NULL || nb_pkts == 0))
                return 0;

-       if(unlikely(!mbufs[0]))
-               for (i = 0; i < RTE_ETH_PCAP_MBUFS; i++)
-                       mbufs[i] = rte_pktmbuf_alloc(pcap_q->mb_pool);
-
        /* Reads the given number of packets from the pcap file one by one
         * and copies the packet data into a newly allocated mbuf to return.
         */
        for (i = 0; i < nb_pkts; i++) {
-               mbuf = mbufs[i % RTE_ETH_PCAP_MBUFS];
+               /* Get the next PCAP packet */
                packet = pcap_next(pcap_q->pcap, &header);
                if (unlikely(packet == NULL))
                        break;
+               else
+                       mbuf = rte_pktmbuf_alloc(pcap_q->mb_pool);
                if (unlikely(mbuf == NULL))
                        break;
-               rte_memcpy(mbuf->pkt.data, packet, header.len);
-               mbuf->pkt.data_len = (uint16_t)header.len;
-               mbuf->pkt.pkt_len = mbuf->pkt.data_len;
-               bufs[i] = mbuf;
-               num_rx++;
+
+               /* Now get the space available for data in the mbuf */
+               mbp_priv = (struct rte_pktmbuf_pool_private *)
+                               ((char *)pcap_q->mb_pool + sizeof(struct rte_mempool));
+               buf_size = (uint16_t) (mbp_priv->mbuf_data_room_size -
+                               RTE_PKTMBUF_HEADROOM);
+
+               if (header.len <= buf_size) {
+                       /* pcap packet will fit in the mbuf, go ahead and copy */
+                       rte_memcpy(mbuf->pkt.data, packet, header.len);
+                       mbuf->pkt.data_len = (uint16_t)header.len;
+                       mbuf->pkt.pkt_len = mbuf->pkt.data_len;
+                       bufs[i] = mbuf;
+                       num_rx++;
+               } else {
+                       /* pcap packet will not fit in the mbuf, so drop packet */
+                       RTE_LOG(ERR, PMD,
+                                       "PCAP packet %d bytes will not fit in mbuf (%d bytes)\n",
+                                       header.len, buf_size);
+                       rte_pktmbuf_free(mbuf);
+               }
        }
        pcap_q->rx_pkts += num_rx;
        return num_rx;
--
1.7.7.6