How to Read Incoming packets from ethernet card?

I have been given this assignment to read incoming IP packets and display their information in a tabular form. It is something similar to the opensource application Wireshark but I have to make the same in matlab . I am very new to matlab and would seek some guidance on the same . I have to display the packer header information i.e. packet size,packet protocol,source,destination.

[Akshat]

Atleast can anyone tell me which function is used to access ethernet packet ?

[Victor Haro]

HI,

Maybe you can USE Tcpdump for mac or linux, or windump for windows.

You can send the results to TXT , example

tcpdump -enni 4 >> text.txt

And you can process the data with Matlab

Regards

Answer 1

[Walter Roberson]

Wireshark and similar programs require privileged access to the ethernet device, as normally programs can only access packets destined for them.

Based upon what I have seen of the interface provided by the Instrument Control Toolbox, I don't expect this facility would be available using those tools.

I think you might have better success using the tcpudpip MATLAB File Exchange contribution. That would, though, in a sense be cheating, in that contribution uses the NetCat libraries that do all of the hard work and then just transfer the packets over to MATLAB.

[Akshat]

Thanks Walter for the valuable input. I discussed the same with my professor and he has asked me to generate the same output but from a stored *.pcap(Packet capture) file. I have found out about the Matshark(SharkTools) dissector tool for Matlab which will read from a stored packet database(Pcap). But that seems to work in a Linux environment(Have to learn that). My question now is :

Do you think it will be possible to display this information from the stored pcap file and will I be able to implement any filters to the same ?

[Walter Roberson]

Should be possible. Once you have the stored packets, the rest is mostly tedium, especially to find the documentation needed to fully decode proprietary protocols.