Re: [PATCH 19.11] app/testpmd: perform SW IP checksum for GRO/GSO packets

[Christian Ehrhardt <christian.ehrhardt@canonical.com>]

On Fri, Jul 8, 2022 at 4:58 AM Wenwu Ma <wenwux.ma@intel.com> wrote:
>
> upstream commit 1945c64674b2b9ad55af0ef31f8a02ae0b747400

Thank you, applied to the WIP branch for 19.11.13

> The GRO/GSO library doesn't re-calculate checksums for
> merged/fragmented packets. If users want the packets to
> have correct IP checksums, they should select HW IP
> checksum calculation for the port which the packets are
> transmitted to. But if the port doesn't support HW IP
> checksum, users may perform a SW IP checksum.
>
> Fixes: b7091f1dcfbc ("app/testpmd: enable the heavyweight mode TCP/IPv4 GRO")
> Fixes: 52f38a2055ed ("app/testpmd: enable TCP/IPv4 VxLAN and GRE GSO")
>
> Signed-off-by: Wenwu Ma <wenwux.ma@intel.com>
> Reviewed-by: Jiayu Hu <jiayu.hu@intel.com>
> Tested-by: Wei Ling <weix.ling@intel.com>
> Acked-by: Yuying Zhang <yuying.zhang@intel.com>
> ---
>  app/test-pmd/csumonly.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c
> index 25091de881..117f14451d 100644
> --- a/app/test-pmd/csumonly.c
> +++ b/app/test-pmd/csumonly.c
> @@ -731,6 +731,26 @@ pkt_copy_split(const struct rte_mbuf *pkt)
>         return md[0];
>  }
>
> +/*
> + * Re-calculate IP checksum for merged/fragmented packets.
> + */
> +static void
> +pkts_ip_csum_recalc(struct rte_mbuf **pkts_burst, const uint16_t nb_pkts, uint64_t tx_offloads)
> +{
> +       int i;
> +       struct rte_ipv4_hdr *ipv4_hdr;
> +       for (i = 0; i < nb_pkts; i++) {
> +               if ((pkts_burst[i]->ol_flags & PKT_TX_IPV4) &&
> +                       (tx_offloads & DEV_TX_OFFLOAD_IPV4_CKSUM) == 0) {
> +                       ipv4_hdr = rte_pktmbuf_mtod_offset(pkts_burst[i],
> +                                               struct rte_ipv4_hdr *,
> +                                               pkts_burst[i]->l2_len);
> +                       ipv4_hdr->hdr_checksum = 0;
> +                       ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
> +               }
> +       }
> +}
> +
>  /*
>   * Receive a burst of packets, and for each packet:
>   *  - parse packet, and try to recognize a supported packet type (1)
> @@ -1038,6 +1058,8 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
>                                 fs->gro_times = 0;
>                         }
>                 }
> +
> +               pkts_ip_csum_recalc(pkts_burst, nb_rx, tx_offloads);
>         }
>
>         if (gso_ports[fs->tx_port].enable == 0)
> @@ -1059,6 +1081,8 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
>
>                 tx_pkts_burst = gso_segments;
>                 nb_rx = nb_segments;
> +
> +               pkts_ip_csum_recalc(tx_pkts_burst, nb_rx, tx_offloads);
>         }
>
>         nb_prep = rte_eth_tx_prepare(fs->tx_port, fs->tx_queue,
> --
> 2.25.1
>


-- 
Christian Ehrhardt
Senior Staff Engineer, Ubuntu Server
Canonical Ltd