Wireshark-users: Re: [Wireshark-users] Where to find documentation about the formats when to read

From: "Maynard, Christopher" <Christopher.Maynard@xxxxxxx>
Date: Wed, 25 Jan 2023 14:31:02 +0000
I think the best place for pyshark support is over at https://github.com/KimiNewt/pyshark/discussions
- Chris

> -----Original Message-----
> From: Wireshark-users <wireshark-users-bounces@xxxxxxxxxxxxx> On
> Behalf Of DIETZ Alexander
> Sent: Wednesday, January 25, 2023 8:43 AM
> To: Community support list for Wireshark <wireshark-
> users@xxxxxxxxxxxxx>
> Subject: Re: [Wireshark-users] Where to find documentation about the
> formats when to read pcapng data with python?
>
> Hello,
>
> I would prefer a description of the format of the data when I read pcapng
> data with python. I do e.g.
>
> cap = pyshark.FileCapture("myfile.pcapng")
>
> then what is "cap"? Seems that this is a list of different "packages". So
> next I do
>
> for pkt in cap: ...
>
> But then what is the content of "pgk"? Is it a list? A dict? A special format?
> With what elements? What are these elements? What types are they (list,
> dict, int, str, something else)?
>
> It turns out each "pkt" object has "layers". What does this mean?
> For my task I need to take the 4th layer
>
> Layer = pkt.layets[3]
>
> But again, what does a layer contain? What elements? What formats? And
> so on.
>
> I managed to figure out myself to extract the data I want, but it might
> probably be much easier if this python structure is somewhere described
> in a proper way.
>
>
> Thanks
>
> -----Original Message-----
> From: Wireshark-users <wireshark-users-bounces@xxxxxxxxxxxxx> On
> Behalf Of Guy Harris
> Sent: Dienstag, 24. Januar 2023 22:22
> To: Community support list for Wireshark <wireshark-
> users@xxxxxxxxxxxxx>
> Subject: Re: [Wireshark-users] Where to find documentation about the
> formats when to read pcapng data with python?
>
> [You don't often get email from gharris@xxxxxxxxx. Learn why this is
> important at https://aka.ms/LearnAboutSenderIdentification ]
>
> This email is not from Hexagon's Office 365 instance. Please be careful
> while clicking links, opening attachments, or replying to this email.
>
>
> On Jan 24, 2023, at 12:37 AM, DIETZ Alexander <alexander.dietz-
> ext@xxxxxxxxxxx> wrote:
>
> > I am very new to wireshark and the pcapng data format used to save
> wireshark recorded data. I want to read that data with python using the
> "pyshark" module, but I cannot find proper documentation on the data
> format(s). The only "extended" documentation I could find is here
> >
> >
> https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fkimi
> newt.github.io%2Fpyshark%2F&data=05%7C01%7C%7Caa9d9f65c9264943
> bbf608dafe50fd11%7C1b16ab3eb8f64fe39f3e2db7fe549f6a%7C0%7C0%7
> C638101921063595507%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLj
> AwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7
> C%7C%7C&sdata=PpdOnY2SNNOksB9zjQldXnUicfGKDVa8ob1MoKNQz1Q
> %3D&reserved=0
> >
> > which I would not consider as extended at all, as the documentation on
> the data format seems to be missing?
> >
> > Is there some other place where the formats of the packages, the layers
> etc. is described in more detail?
>
> Pcapng files, like pcap files, Sniffer files, Network Monitor files, etc., are
> sequences of one or more records, in a particular format.  Packet records
> contain metadata such as packet lengths and time stamps, as well as a
> blob of raw data.
>
> The blob of raw data may contain additional metadata, followed by raw
> packet data.
>
> Do you want the format of the records in those files described, do you
> want the format of the raw data blobs described, or both?
>
> From "the formats of the packages, the layers etc." it sounds as if you want
> the format of the raw data blobs described.  For example, if the packets
> are Ethernet packets, they begin with a 14-byte Ethernet header; if the
> type/length field in the Ethernet header has a type value rather than a
> length value, the type value indicates the type of packet that follows the
> 14-byte header.  A value of 0x0800, for example, means that the packet is
> an IPv4 packet, which begins with a header as described by RFC 791, and
> so on.






CONFIDENTIALITY NOTICE: This message is the property of International Game Technology PLC and/or its subsidiaries and may contain proprietary, confidential or trade secret information. This message is intended solely for the use of the addressee. If you are not the intended recipient and have received this message in error, please delete this message from your system. Any unauthorized reading, distribution, copying, or other use of this message or its attachments is strictly prohibited.