Re: [dpdk-dev] pktgen offload checksum flag not able to make it work with pacp packets.

[Vladimir Medvedkin <medvedkinv@gmail.com>]

Hi Banashankar,

For proper TCP checksum calculation you have to calculate checksum over
pseudo header (see app/test-pmd/cmdline.c) and put result in tcp_hdr->cksum


2014-01-26 Wiles, Roger Keith <keith.wiles@windriver.com>

> Hi Banashankar,
>
> The tx_conf is used in the pktgen_config_ports() with the
> rte_eth_tx_queue_setup() and I am not sure why it matters that tx_conf is
> disable. The values are mostly zero, but some type of interaction must be
> going on. It may be the txq_flags being set to  IXGBE_SIMPLE_FLAGS and it
> is overriding the the per packet flag later. You will need to look at the
> driver to determine the real reason.
>
> The checksum should not be wrong unless the hardware registers are not
> setup correctly, but I would not think that is the case. You may want to
> verify the checksum is correct another way, because I can not see the
> hardware doing the checksum wrong.
>
> Thanks
> ++Keith
>
>
> Keith Wiles, Principal Technologist for Networking member of the CTO
> office, Wind River
> mobile 940.213.5533
> [Powering 30 Years of Innovation]<http://www.windriver.com/announces/wr30/
> >
>
> On Jan 25, 2014, at 4:53 PM, Banashankar KV <banveerad@gmail.com<mailto:
> banveerad@gmail.com>> wrote:
>
> Hi,
> Thanks a lot for the reply !
> Yes I have checked those examples and had set all those flags. But IP
> checksum started working after commenting off the txq_flags from
> the pktgen.c file's tx_conf .
>
> And I added the following flag to calculate the tcp checksum.
>
> m->ol_flags  |= PKT_TX_TCP_CKSUM
>
> its calculating the TCP checksum but turning out to be wrong checksum.
>
> Thanks
> Banashankar
>
>
>
> On Fri, Jan 24, 2014 at 11:44 AM, Wiles, Roger Keith <
> keith.wiles@windriver.com<mailto:keith.wiles@windriver.com>> wrote:
> I have not enabled that feature myself, but I would expect it to work as
> long as the hardware does. What does the docs say about enabling hardware
> offload support? Did you look at the following files:
>
> ip_reassembly/ipv4_rsmbl.h:     m->ol_flags |= PKT_TX_IP_CKSUM;
> ipv4_frag/rte_ipv4_frag.h:              out_pkt->ol_flags |=
> PKT_TX_IP_CKSUM;
>
> Thanks
> ++Keith
>
> Keith Wiles, Principal Technologist for Networking member of the CTO
> office, Wind River
> mobile 940.213.5533<tel:940.213.5533>
> [Powering 30 Years of Innovation]<http://www.windriver.com/announces/wr30/
> >
>
> On Jan 24, 2014, at 12:54 PM, Banashankar KV <banveerad@gmail.com<mailto:
> banveerad@gmail.com>> wrote:
>
> I was modifying a packet in pktgen_pcap_mbuf_ctor()
> and after modifying I wanted to offload the checksum calculation to h/w
> so I am setting these flags in pktgen_pcap_mbuf_ctor function.
>
> m->pkt.vlan_macip.f.l2_len = sizeof(struct ether_hdr);
> m->pkt.vlan_macip.f.l3_len = sizeof(struct ipv4_hdr);
>
> m->ol_flags = PKT_TX_IP_CKSUM
>
>
> I even tried with setting .txq_flags = 0 in rte_eth_txconf struct in
> pktgen.c.
>
> But still not able to get the h/w checksum. Am I missing anything ?
>
>
>
> Thanks
> Banashankar
>
>
>
> Regards,
Vladimir