[tcpdump-workers] Link-layer header type request for libopenvizsla

[Guy Harris]

On Aug 25, 2018, at 1:10 PM, Matwey V. Kornilov <matwey.kornilov at gmail.com> wrote:

> Answering your questions and Michael question, the url describes the
> data coming from the hardware as is. Its format is defined by the
> people developing FPGA firmware, that is currently not quite active:
> https://github.com/openvizsla/ov_ftdi/tree/master/software/fpga So it
> is unlikely that the format will change dramatically, but I just would
> like to follow initial format as close as possible.

I suspected that's what the FPGA delivered.

> However, I agree that we can just use the following simple
> representation for pcap:
> 
> struct {
>  uint32_t timestamp;
>  uint16_t flags;
>  uint8_t usb_packet[];
> };

So your code to construct pcap files (or your libpcap module) would shuffle the header data around before providing the packet?

> OpenVizsla supports only USB 2.0: low, full and high speed.

So we can just point to the USB 2.0 specification.