Developing tiny Arduino packet sniffer

Question

I'm trying to develop a simple packet sniffer using Arduino, I just wanted to save the TCP/IP packet information on the memory card, I want to know if there is any way using Arduino Ethernet library or even w5100 library to get access to the received packet's header fields and information. at least I need ten fields from the header like source and dest IP/Port, protocol, length, checksum ....

Answer 1

The libraries are open source, so if they do not provide a method to get that information then you can add one. You will need to initially read the *.h files for the W5100 libs and see if there are any prototypes that might do what you want.

I personally have browsed the libs for the ENC28J60 ethernet chip and have looked at a little bit of code for the W5100 libs. All of the TCP/IP header information is there (it has to be, by definition).

So, if you are a programmer it should not be too difficult to log that info. (assuming of course that the W5100 libs don't already provide the methods to do so).