Wireshark mailing list archives
Re: XML library for use in dissector
From: Peter Wu <peter () lekensteyn nl>
Date: Sun, 29 Jan 2017 15:52:09 +0100
Hi Ahmad, On Sat, Jan 28, 2017 at 08:04:11PM +0100, Ahmad Fatoum wrote:
Hello everyone, As part of a school project, we intend to extend the Ethernet POWERLINK (packet-epl.c) dissector in Wireshark to be able to read in the XML device description files (XDD) and use that information to dissect the packet payload (The data field is currently displayed as a byte stream). As we would like to have the changes eventually merged into the trunk, we want to check what XML library we should use? We are hesitant to rely on GMarkup, because we don't control the input, and don't want to later find out that it doesn't manage some more complex device profiles. Wireshark depends on lex(1), but I wouldn't want to reinvent the wheel and rather use some out-of-the-box parser. So what's the stance on dissectors pulling in dependencies like libxml? Any other suggestions?
Some (family of) dissectors are generated from description files (ASN.1, PIDL, ...). These "compilers" are Python/Perl/... programs which sometimes have additional dependencies at the time of generation, but are otherwise just normal C dissectors without additional dependencies after generation. Would this method of generating a dissector help? You can find some examples in epan/dissectors/asn1/, epan/dissectors/pidl/, epan/dissectors/README.X11. If the XML files describing the payload vary at runtime, I do not have a particular suggestion for an approach.
With kind regards Ahmad Fatoum ps: Out of curiosity, is there a particular reason e.g. PROFINET is a plugin while Ethernet POWERLINK is statically linked?
Most dissectors are located in epan/dissectors/ (statically linked). I guess someone started with the PROFINET dissector as plugin and it just continued living there. -- Kind regards, Peter Wu https://lekensteyn.nl ___________________________________________________________________________ Sent via: Wireshark-dev mailing list <wireshark-dev () wireshark org> Archives: https://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://www.wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-request () wireshark org?subject=unsubscribe
Current thread:
- XML library for use in dissector Ahmad Fatoum (Jan 28)
- Re: XML library for use in dissector Peter Wu (Jan 29)
- <Possible follow-ups>
- Re: XML library for use in dissector Ahmad Fatoum (Jan 30)