This is our old Q&A Site. Please post any new questions and answers at

Hi, I'm expecting to work with Wireshark software in a commercial projet environment. Wireshark is licensed under the GNU General Public License. But what about the plugin source code I develop for a well-known protocol but specific for our application ? The source code of Wireshark software is not modified and development of the plug-in is not, in my mind, a "derivative work" according to GPL definition. On Lua site, it is written : … Even if the code you write in Lua does not need to be GPL'ed. The code written in Lua that uses bindings to Wireshark must be distributed under the GPL terms... So I don't know ! Any help will be certainly appreciated

asked 02 Jul '12, 07:16

patcas29's gravatar image

accept rate: 0%

I would say, you have to apply the GPL to your plugin.


If the program dynamically links plug-ins, and they make function calls to each other and share data structures, we believe they form a single program

The marked part is true for a Wireshark plugin.

Then, you could argue, that the plugin is not really dynamically linked to the main program, as the plugin is loaded at runtime and that's why it is different than in the desription above.

That might be a valid argument, as also described in that link:

It depends on how the program invokes its plug-ins. If the program uses fork and exec to invoke plug-ins, then the plug-ins are separate programs, so the license for the main program makes no requirements for them.

Unfortunately I can't finally answer that one.

I would tend to say, that your plugin has to be GPLed, as it is using all the internal data structures and the code of Wireshark.


permanent link

answered 02 Jul '12, 08:00

Kurt%20Knochner's gravatar image

Kurt Knochner ♦
accept rate: 15%

edited 02 Jul '12, 10:03

Everything using Wireshark's API's, not 'at arms length', is covered by the GPL. That applies to plugins, which are basically an extension of the Ethereal Packet ANalyzer (EPAN) part of *shark. Being 'at arms length' is considered something that interacts through OS means, like a pipe or something.

Is that a problem? No. Why? Because GPL has to do with distribution. As long as you don't distribute your dissector, you can do what you like. But if you do distribute then your bound by the rule that you have to provide the source code under GPL license.

permanent link

answered 03 Jul '12, 00:56

Jaap's gravatar image

Jaap ♦
accept rate: 14%

Your answer
toggle preview

Follow this question

By Email:

Once you sign in you will be able to subscribe for any updates here



Answers and Comments

Markdown Basics

  • *italic* or _italic_
  • **bold** or __bold__
  • link:[text]( "title")
  • image?![alt text](/path/img.jpg "title")
  • numbered list: 1. Foo 2. Bar
  • to add a line break simply add two spaces to where you would like the new line to be.
  • basic HTML tags are also supported

Question tags:


question asked: 02 Jul '12, 07:16

question was seen: 7,749 times

last updated: 03 Jul '12, 00:56

p​o​w​e​r​e​d by O​S​Q​A