RE: [PATCH] net/pcap: support MTU set

[Ido Goshen <Ido@cgstowernetworks.com>]

af_packet is hard coded limited to 1518 bytes so it cannot be used for jumbo

Indifferent, why is it better that pcap would NOT support api that all other pmds do (especially if it doesn't change legacy behavior when it's not used)?

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@amd.com>
> Sent: Monday, 10 July 2023 20:47
> To: Stephen Hemminger <stephen@networkplumber.org>; Ido Goshen
> <Ido@cgstowernetworks.com>
> Cc: Ferruh Yigit <ferruh.yigit@intel.com>; dev@dpdk.org
> Subject: Re: [PATCH] net/pcap: support MTU set
> 
> On 7/10/2023 5:45 PM, Stephen Hemminger wrote:
> > On Thu, 17 Mar 2022 19:43:47 +0200
> > ido g <ido@cgstowernetworks.com> wrote:
> >
> >> Support rte_eth_dev_set_mtu by pcap vdevs Enforce mtu on rx/tx For
> >> more details see https://bugs.dpdk.org/show_bug.cgi?id=961
> >>
> >> Signed-off-by: ido g <ido@cgstowernetworks.com>
> >
> > Feeling less convinced that this is needed.
> > The motivation appears to be to test with an underlying Linux device.
> > If so, then why not use af_packet or tap devices which already should
> handle MTU?
> >
> 
> I am feeling similar for case that requires underlying physical device.
> 
> If there is a need/use case for .pcap file, as far as I can see v4 version of this
> set is handling .pcap file case.