ANNOUNCEMENT: Live Wireshark University & Allegro Packets online APAC Wireshark Training Session
July 17th, 2024 | 10:00am-11:55am SGT (UTC+8) | Online

Wireshark-dev: Re: [Wireshark-dev] [Wireshark-commits] rev 27748:/trunk/plugins/profinet/ /trun

From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Mon, 16 Mar 2009 17:19:16 -0700

On Mar 16, 2009, at 4:33 PM, Ulf Lamping wrote:

I'm not an expert on this stuff, so it might be easy to rewrite the
existing CRC stuff - but I'm really not an expert on this ...

I'm not, either, but I updated the comment in epan/crc16.c to point to Ross Williams' Web site, where he has links to a text and an HTML version of his paper. It has a copy of the algorithm used to generate the CRC16 tables for a given polynomial; if you can use it to generate the table for the PROFINET CRC16 (so that the numbers are the same as the ones in the plugins/profinet/crc16.c file), and make the changes to epan/crc16.c to expose the CRC16 routine that takes a table as an argument, that should let you use the libwireshark CRC16 routine.

(In addition, reading the paper would make you more of an expert on it - more of an expert than me, at least. :-))