On 7/24/2019 12:54 PM, David Marchand wrote:
> When a packet cannot be transmitted, the driver is supposed to free this
> packet and report it as handled.
> This is to prevent the application from retrying to send the same packet
> and ending up in a liveloop since the driver will never manage to send
> it.
>
> Fixes: 49a0a2ffd5db ("net/pcap: fix possible mbuf double freeing")
> Fixes: 6db141c91e1f ("pcap: support jumbo frames")
> CC: sta...@dpdk.org
>
> Signed-off-by: David Marchand <david.march...@redhat.com>
> ---
> drivers/net/pcap/rte_eth_pcap.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/pcap/rte_eth_pcap.c b/drivers/net/pcap/rte_eth_pcap.c
> index 470867d..5e5aab7 100644
> --- a/drivers/net/pcap/rte_eth_pcap.c
> +++ b/drivers/net/pcap/rte_eth_pcap.c
> @@ -354,7 +354,8 @@ struct pmd_devargs_all {
> mbuf->pkt_len,
> RTE_ETHER_MAX_JUMBO_FRAME_LEN);
>
> - break;
> + rte_pktmbuf_free(mbuf);
> + continue;
+1
Very recently 'rte_pktmbuf_free()' was moved because it wasn't compatible with
return value, but this looks better, to free the mbuf and record it as error.
> }
> }
>
> @@ -373,7 +374,7 @@ struct pmd_devargs_all {
> dumper_q->tx_stat.bytes += tx_bytes;
> dumper_q->tx_stat.err_pkts += nb_pkts - num_tx;
>
> - return num_tx;
> + return nb_pkts;
> }
>
> /*
> @@ -439,14 +440,15 @@ struct pmd_devargs_all {
> mbuf->pkt_len,
> RTE_ETHER_MAX_JUMBO_FRAME_LEN);
>
> - break;
> + rte_pktmbuf_free(mbuf);
> + continue;
> }
> }
>
> - if (unlikely(ret != 0))
> - break;
> - num_tx++;
> - tx_bytes += mbuf->pkt_len;
> + if (ret == 0) {
> + num_tx++;
> + tx_bytes += mbuf->pkt_len;
> + }
I don't know this part, this is in 'eth_pcap_tx()' which writes packets to the
interfaces.
if 'pcap_sendpacket()' fails this doesn't mean packet can't be sent and may
cause a liveloop. Why not keep the existing behavior and let application to
decide?
> rte_pktmbuf_free(mbuf);
> }
>
> @@ -454,7 +456,7 @@ struct pmd_devargs_all {
> tx_queue->tx_stat.bytes += tx_bytes;
> tx_queue->tx_stat.err_pkts += nb_pkts - num_tx;
>
> - return num_tx;
> + return nb_pkts;
> }
>
> /*
>
