Re: How to debug receiving error or "rte_eth_stats.ierrors" ...

[Pavel Vazharov <freakpv@gmail.com>]

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Few questions:
1. Does the sending NIC support IP and TCP/UDP checksum offloading? I mean,
if these flags set?
    struct rte_eth_dev_info dev_info;

    rte_eth_dev_info_get(cfg.nic_port_id_, &dev_info);
    constexpr auto rxcsum = DEV_RX_OFFLOAD_CHECKSUM;

    constexpr auto l3csum = DEV_TX_OFFLOAD_IPV4_CKSUM;

    constexpr auto l4csum = DEV_TX_OFFLOAD_TCP_CKSUM |
DEV_TX_OFFLOAD_UDP_CKSUM;
    dev_rx_csum_          = ((dev_info.tx_offload_capa & rxcsum) ==
rxcsum);
    dev_tx_csum_l3_       = ((dev_info.tx_offload_capa & l3csum) ==
l3csum);
    dev_tx_csum_l4_       = ((dev_info.tx_offload_capa & l4csum) == l4csum);

2. Do you "tell" the sending NIC to do the checksum calculations before
sending the packets? I mean, do you do something like this for outgoing
packets?
    if (offl.ip_csum) {

        pkt->ol_flags |= PKT_TX_IP_CKSUM | PKT_TX_IPV4;

        pkt->l2_len = RTE_ETHER_HDR_LEN;

        pkt->l3_len = ih_len;

    }

    if (offl.tcp_csum) {

        pkt->ol_flags |= PKT_TX_TCP_CKSUM;

        pkt->l2_len = RTE_ETHER_HDR_LEN;

        pkt->l3_len = ih_len;

    }

    if (offl.udp_csum) {

        pkt->ol_flags |= PKT_TX_UDP_CKSUM;

        pkt->l2_len = RTE_ETHER_HDR_LEN;

        pkt->l3_len = ih_len;

    }

3. Is the receiving side also a DPDK application? If it is, and if the NIC
there supports checksum offloading you can check the flags of the received
packets to see if the receiving NIC has detected checksum errors.
pkt->ol_flags & (PKT_RX_IP_CKSUM_BAD | PKT_RX_L4_CKSUM_BAD)

Hope some of the above helps.

On Thu, Dec 8, 2022 at 9:36 AM Ruslan R. Laishev <zator@yandex.ru> wrote:

> Hello !
>
> I wrote too small apps to send and receive  ethernet/ip/udp
> frame/packet/dg, so on received side I  see next situation:
> number of in errors is equally a number of received packets. The test
> packet I made manually,  set offloads  IP/UDP checkusm.
> Is there what I'm need to check additionally ?
>
>

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