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

2018-09-12 Thread Guy Harris 
On Aug 25, 2018, at 1:27 PM, Guy Harris  wrote:

> On Aug 25, 2018, at 1:10 PM, Matwey V. Kornilov  
> 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?

So which would be better:

1) the raw data from


https://github.com/matwey/libopenvizsla/wiki/OpenVizsla-protocol-description

   is what's in the packet in a pcap or pcapng file, and we just note 
that the Size field is redundant (it's the captured length minus 8 for the 
header)

or

2) the simple representation?

We can do either one.
___
tcpdump-workers mailing list
tcpdump-workers@lists.tcpdump.org
https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers

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

2018-09-12 Thread Matwey V. Kornilov 
сб, 1 сент. 2018 г. в 5:37, Michael Richardson :
>
>
> https://github.com/the-tcpdump-group/libpcap/commit/a69f42f7873db778613bbd5c4238acc2d0c31c89
>
> /*
>   * OpenVizsla http://openvizsla.org is open source USB analyzer hardware.
>   * It consists of FPGA with attached USB phy and FTDI chip for streaming
>   * the data to the host PC.
>   *
>   * Current OpenVizsla data encapsulation format is described here:
>   * 
> https://github.com/matwey/libopenvizsla/wiki/OpenVizsla-protocol-description
>   *
>   */
>  #define LINKTYPE_OPENVIZSLA 278
>
> 
>
> http://www.tcpdump.org/linktypes/LINKTYPE_OPENVIZSLA.html
>
> If you want changes, or if you'd like us to archive the format here,
> then send pull request against:
>  https://github.com/the-tcpdump-group/tcpdump-htdocs

Thank you.

For the reference, the link to the sources:
https://github.com/matwey/libpcap/tree/openvizsla

>
> --
> ]   Never tell me the odds! | ipv6 mesh networks [
> ]   Michael Richardson, Sandelman Software Works| network architect  [
> ] m...@sandelman.ca  http://www.sandelman.ca/|   ruby on rails
> [
>


-- 
With best regards,
Matwey V. Kornilov
___
tcpdump-workers mailing list
tcpdump-workers@lists.tcpdump.org
https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers