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From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
To: Alex Markuze <alex@weka.io>, "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] UDP Checksum
Date: Thu, 6 Nov 2014 16:15:24 +0000
Message-ID: <2601191342CEEE43887BDE71AB977258213A2E79@IRSMSX105.ger.corp.intel.com> (raw)
In-Reply-To: <CAKfHP0WWCrftSR=z=jvUsHCLtTZdBwch0ZvadiLa9nMfcbpW-Q@mail.gmail.com>



> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Alex Markuze
> Sent: Thursday, November 06, 2014 4:05 PM
> To: dev@dpdk.org
> Subject: [dpdk-dev] UDP Checksum
> 
> Hi,
> I'm seeing "UDP: bad checksum." messages(dmesg) for packets sent by my dpdk
> app to a socket on a remote machine.
> Looking at the packets the scum value is set, its just not what wireshark
> expects.
> 
> When sending I'm setting these fields in the egress packets.
> 
>         pkt->pkt.vlan_macip.f.l2_len = sizeof(struct ether_hdr);
> 
>         pkt->pkt.vlan_macip.f.l3_len = sizeof(struct ipv4_hdr);
> 
>         pkt->ol_flags |= (PKT_TX_IP_CKSUM | PKT_TX_L4_MASK);
> //PKT_TX_OFFLOAD_MASK;
> 
> 
> I'm working with a 82599 VF.
> 
> 
> Any thoughts? I'm not sure what else to check.

As I remember, you have to setup  IPV4 header checksum to 0 and
calculate and setup pseudo-header checksum for UDP.
From app/test-pmd/csumonly.c:
...
if (pkt_ol_flags & (PKT_RX_IPV4_HDR | PKT_RX_TUNNEL_IPV4_HDR)) {

                        /* Do not support ipv4 option field */
                        l3_len = sizeof(struct ipv4_hdr) ;

                        ...

                        /* Do not delete, this is required by HW*/
                        ipv4_hdr->hdr_checksum = 0;

                       ...
   
                      if (l4_proto == IPPROTO_UDP) {
                                udp_hdr = (struct udp_hdr*) (rte_pktmbuf_mtod(mb,
                                                unsigned char *) + l2_len + l3_len);
                                if (tx_ol_flags & 0x2) {
                                        /* HW Offload */
                                        ol_flags |= PKT_TX_UDP_CKSUM;
                                        if (ipv4_tunnel)
                                                udp_hdr->dgram_cksum = 0;
                                        else
                                                /* Pseudo header sum need be set properly */
                                                udp_hdr->dgram_cksum =
                                                        get_ipv4_psd_sum(ipv4_hdr);




  parent reply	other threads:[~2014-11-06 16:06 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-06 16:05 Alex Markuze
2014-11-06 16:15 ` Olivier MATZ
2014-11-06 16:15 ` Ananyev, Konstantin [this message]
2014-11-06 16:26   ` Alex Markuze
     [not found]     ` <2601191342CEEE43887BDE71AB977258213A2EC5@IRSMSX105.ger.corp.intel.com>
2014-11-06 17:07       ` Ananyev, Konstantin
2019-09-24 15:11 [dpdk-dev] udp checksum Khoussi, Siham (IntlAssoc)

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