[dpdk-users] Is it possible to receive packets with bad CRC?

[Stephen Hemminger]

On Tue, 8 Jun 2021 11:44:10 +0800
"JieSong" <songj at zctt.com> wrote:

> Hi Ido,
>     I have the same question as yours, I want to get all the packets even the CRC/FCS error packet.
>     Without DPDK I set the nic with "ethtool -K rx-all on", Then i can tcpdump all the packets both good and error packets.
>     But I have no ideal with DPDK. Did you find something for this question? 
> 
> 
> Thanks
> 
> 
> Jie
> 
> 
> 
>  
>  
>  
> ------------------ Original ------------------
> From:  "Ido Goshen"<Ido at cgstowernetworks.com>;
> Date:  Mon, Dec 14, 2020 00:56 AM
> To:  "users at dpdk.org"<users at dpdk.org>; 
> 
> Subject:  [dpdk-users] Is it possible to receive packets with bad CRC?
> 
>  
> 
> Hi
> 
> By default bad CRC packets are dropped and raise the ierror counter.
> 
> Is there a way to change this behavior for I350 (igb) and rx it by the app?
> 
> I’ve tried setting DEV_RX_OFFLOAD_KEEP_CRC but this doesn’t help (I think this only keeps CRC for good packets)
> I’ve also tried enabling the Store Bad Packet (not sure what it does but it’s the closet I could find) by setting in e1000/igb_rxtx.c
> rctl |= E1000_RCTL_SBP;  E1000_WRITE_REG(hw, E1000_RCTL, rctl);
> Didn’t help either.
> 
> Is it possible to do with I350?
> Or with any of the other intel NICs? X522 (ixgbe) or X710 (i40e)?
> 
> Thanx,
> 
>   *   Ido


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The DPDK ethdev API does not have a way to enable storing bad packets.
The DPDK ixgbe driver has a device specific API call rte_pmd_ixgbe_udp_fctrl_sbp which may
do what you want.  Device specific API's are discouraged but possible.