This chapter will provide you with information about Wireshark development in general.

Well, if you want to start Wireshark development, you might already know what Wireshark is doing. If not, please have a look at the Wireshark User's Guide, which will provide a lot of general information about it.

Wireshark currently runs on most UNIX platforms and various Windows platforms. It requires GTK+, GLib, libpcap and some other libraries in order to run. As Wireshark is developed in a platform independent way and uses libraries (such as the GTK+ GUI library) which are available for a lot of different platforms, it's thus available on a wide variety of platforms. If a binary package is not available for your platform, you should download the source and try to build it. Please report your experiences to &WiresharkDevMailList;. Binary packages are available for at least the following platforms:

Apple Mac OS X BeOS FreeBSD HP-UX IBM AIX NetBSD OpenBSD SCO UnixWare/OpenUnix SGI Irix Sun Solaris/Intel Sun Solaris/Sparc Tru64 UNIX (formerly Digital UNIX)

Debian GNU/Linux Ubuntu Gentoo Linux IBM S/390 Linux (Red Hat) Mandrake Linux PLD Linux Red Hat Linux Rock Linux Slackware Linux Suse Linux

Thanks to the Win32 API, development on all Windows platforms will be done in a very similar way. All Windows platforms referred to as Win32, Win or Windows may be used with the same meaning. Older Windows versions are no longer supported by Wireshark. As Windows CE differs a lot compared to the other Windows platforms mentioned, Wireshark will not run on Windows CE and there are no plans to support it. Also the 64 bit Windows version are now supported by Wireshark. Although not all libraries are made 64 bit ready yet, basic operations are all available. Windows Server 2000 Windows XP Windows Server 2003 Windows Vista Windows 7 Windows Server 2008

Wireshark was initially developed by Gerald Combs. Ongoing development and maintenance of Wireshark is handled by the Wireshark core developers, a loose group of individuals who fix bugs and provide new functionality. There have also been a large number of people who have contributed protocol dissectors and oher improvements to Wireshark, and it is expected that this will continue. You can find a list of the people who have contributed code to Wireshark by checking the About dialog box of Wireshark, or have a look at the page on the Wireshark web site. The communication between the developers is usually done through the developer mailing list, which can be joined by anyone interested in the development activities. At the time this document was written, more than 500 persons were subscribed to this mailing list! It is strongly recommended to join the developer mailing list, if you are going to do any Wireshark development. See about the different Wireshark mailing lists available.

Almost any part of Wireshark is implemented in plain ANSI C. The typical task for a new Wireshark developer is to extend an existing, or write a new dissector for a specific network protocol. As (almost) any dissector is written in plain old ANSI C, a good knowledge about ANSI C will be sufficient for Wireshark development in almost any case. So unless you are going to change the build process of Wireshark itself, you won't come in touch with any other programming language than ANSI C (such as Perl or Python, which are used only in the Wireshark build process). Beside the usual tools for developing a program in C (compiler, make, ...), the build process uses some additional helper tools (Perl, Python, Sed, ...), which are needed for the build process when Wireshark is to be build and installed from the released source packages. If Wireshark is installed from a binary package, none of these helper tools are needed on the target system.

Wireshark is an open source software (OSS) project, and is released under the GNU General Public License (GPL). You can freely use Wireshark on any number of computers you like, without worrying about license keys or fees or such. In addition, all source code is freely available under the GPL. Because of that, it is very easy for people to add new protocols to Wireshark, either as plugins, or built into the source, and they often do! You are welcome to modify Wireshark to suit your own needs, and it would be appreciated if you contribute your improvements back to the Wireshark community. You gain three benefits by contributing your improvements back to the community: Other people who find your contributions useful will appreciate them, and you will know that you have helped people in the same way that the developers of Wireshark have helped you and other people. The developers of Wireshark might improve your changes even more, as there's always room for improvement. Or they may implement some advanced things on top of your code, which can be useful for yourself too. The maintainers and developers of Wireshark will maintain your code as well, fixing it when API changes or other changes are made, and generally keeping it in tune with what is happening with Wireshark. So if Wireshark is updated (which is done often), you can get a new Wireshark version from the website and your changes will already be included without any effort for you. The Wireshark source code and binary packages for some platforms are all available on the download page of the Wireshark website: &WiresharkDownloadPage;.

The officially released files can be found at: . A new Wireshark version is released after significant changes compared to the last release are completed or a serious security issue is encountered. The typical release schedule is about every 4-8 weeks (although this may vary). There are two kinds of distributions: binary and source; both have their advantages and disadvantages.

Binary distributions are usually easy to install (as simply starting the appropriate file is usually the only thing to do). They are available for the following systems: Windows (.exe file). The typical Windows end user is used to get a setup.exe file which will install all the required things for him. Win32 U3 (.u3 file). Special distribution for U3 capable USB memory sticks. Win32 PAF (.paf.exe file). Another Windows end user method is to get a portable application file which will install all the required things for him. Debian (.deb file). A user of a Debian Package Manager (DPKG) based system obtains a .deb file from which the package manager checks the dependencies and installs the software. Red Hat (.rpm file). A user of a Red Hat Package Manager (RPM) based system obtains an .rpm file from which the package manager checks the dependencies and installs the software. MAC OS X (.dmg file). The typical MAC OS X end user is used to get a .dmg file which will install all the required things for him. The other requirement is to have the X11.app installed. Solaris. A Solaris user obtains a file from which the package manager (PKG) checks the dependencies and installs the software. However, if you want to start developing with Wireshark, the binary distributions won't be too helpful, as you need the source files, of course. For details about how to build these binary distributions yourself, e.g. if you need a distribution for a special audience, see .

It's still common for UNIX developers to give the end user a source tarball and let the user compile it on their target machine (configure, make, make install). However, for different UNIX (Linux) distributions it's becoming more common to release binary packages (e.g. .deb or .rpm files) these days. You should use the released sources if you want to build Wireshark from source on your platform for productive use. However, if you going to develop changes to the Wireshark sources, it might be better to use the latest SVN sources. For details about the different ways to get the Wireshark source code see . Before building Wireshark from a source distribution, make sure you have all the tools and libraries required to build. The following chapters will describe the required tools and libraries in detail.

The Wireshark Buildbot automatically rebuilds Wireshark on every change of the source code repository and indicates problematic changes. This frees the developers from repeating (and annoying) work, so time can be spent on more interesting tasks.

Recognizing (cross platform) build problems - early. Compilation problems can be narrowed down to a few commits, making a fix much easier. "Health status" overview of the sources. A quick look at: gives a good "feeling" if the sources are currently "well". On the other hand, if all is "red", an update of a personal source tree might better be done later ... "Up to date" binary packages are available. After a change was committed to the repository, a binary package / installer is usually available within a few hours at: . This can be quite helpful, e.g. a bug reporter can easily verify a bugfix by installing a recent build. Automated regression tests. In particular, the fuzz tests often indicate "real life" problems that are otherwise hard to find.

The Buildbot will do the following (to a different degree on the different platforms): checkout from the source repository build create binary package(s) / installer create source package (and check completeness) run regression tests Each step is represented at the status page by a rectangle, green if it succeeded or red if it failed. Most steps provide a link to the corresponding console logfile, to get additional information. The Buildbot runs on a platform collection that represents the different "platform specialties" quite well: Windows XP x86 (Win32, little endian, VS 9) Windows XP x86-64 (Win64, little endian, VS 9) Ubuntu x86-64 (Linux, little endian, gcc) Solaris SPARC (Solaris, big endian, gcc) Mac OS-X PPC (BSD, big endian, gcc) Mac OS-X x86 (BSD, little endian, gcc) Each platform is represented at the status page by a single column, the most recent entries are at the top.

If you have problems, or need help with Wireshark, there are several places that may be of interest to you (well, beside this guide of course).

You will find lot's of useful information on the Wireshark homepage at &WiresharkWebSite;.

The Wireshark Wiki at &WiresharkWikiSite; provides a wide range of information related to Wireshark and packet capturing in general. You will find a lot of information not part of this developer's guide. For example, there is an explanation how to capture on a switched network, an ongoing effort to build a protocol reference and a lot more. And best of all, if you would like to contribute your knowledge on a specific topic (maybe a network protocol you know well), you can edit the wiki pages by simply using your webbrowser.

The "Frequently Asked Questions" will list often asked questions and the corresponding answers. Before sending any mail to the mailing lists below, be sure to read the FAQ, as it will often answer the question(s) you might have. This will save yourself and others a lot of time (keep in mind that a lot of people are subscribed to the mailing lists). You will find the FAQ inside Wireshark by clicking the menu item Help/Contents and selecting the FAQ page in the upcoming dialog. An online version is available at the Wireshark website: &WiresharkFAQPage;. You might prefer this online version, as it's typically more up to date and the HTML format is easier to use.

If you don't find the information you need inside this book, there are various other sources of information: the file doc/README.developer and all the other README.xxx files in the source code - these are various documentation files on different topics The README.developer is packed full with all kinds of details relevant to the developer of Wireshark source code. It advices you around common pitfalls, shows you basic layout of dissector code, shows details of the API's available to the dissector developer, etc. the Wireshark source code tool documentation of the various tools used (e.g. manpages of sed, gcc, ...) the different mailing lists: see ...

There are several mailing lists available on specific Wireshark topics: wireshark-announce This mailing list will inform you about new program releases, which usually appear about every 4-8 weeks. wireshark-users This list is for users of Wireshark. People post questions about building and using Wireshark, others (hopefully) provide answers. wireshark-dev This list is for Wireshark developers. People post questions about the development of Wireshark, others (hopefully) provide answers. If you want to start developing a protocol dissector, join this list. wireshark-bugs This list is for Wireshark developers. Every time a change to the bug database occurs, a mail to this mailing list is generated. If you want to be notified about all the changes to the bug database, join this list. Details about the bug database can be found in . wireshark-commits This list is for Wireshark developers. Every time a change to the SVN repository is checked in, a mail to this mailing list is generated. If you want to be notified about all the changes to the SVN repository, join this list. Details about the SVN repository can be found in . You can subscribe to each of these lists from the Wireshark web site: &WiresharkWebSite;. Simply select the mailing lists link on the left hand side of the site. The lists are archived at the Wireshark web site as well. You can search in the list archives to see if someone previously asked the same question and maybe already got an answer. That way you don't have to wait until someone answers your question.

The Wireshark community collects bug reports in a Bugzilla database at &WiresharkBugsSite;. This database is filled with manually filed bug reports, usually after some discussion on wireshark-dev, and automatic bug reports from the buildbot tools.

Before reporting any problems, please make sure you have installed the latest version of Wireshark. Reports on older maintainance releases are usually met with an upgrade request. If you report problems, provide as much information as possible. In general, just think about what you would need to find that problem, if someone else sends you such a problem report. Also keep in mind that people compile/run Wireshark on a lot of different platforms. When reporting problems with Wireshark, it is helpful if you supply the following information: The version number of Wireshark and the dependent libraries linked with it, e.g. GTK+, etc. You can obtain this with the command wireshark -v. Information about the platform you run Wireshark on. A detailed description of your problem. If you get an error/warning message, copy the text of that message (and also a few lines before and after it, if there are some), so others may find the build step where things go wrong. Please don't give something like: "I get a warning when compiling x" as this won't give any direction to look at. Do not send large files (>100KB) to the mailing lists, just place a note that further data is available on request. Large files will only annoy a lot of people on the list who are not interested in your specific problem. If required, you will be asked for further data by the persons who really can help you. If you send captured data to the mailing lists, or add it to your bug report, be sure it doesn't contain any sensitive or confidential information, such as passwords. Visibility of such files can be limited to certain groups in the Bugzilla database though.

When reporting crashes with Wireshark, it is helpful if you supply the traceback information (besides the information mentioned in ). You can obtain this traceback information with the following commands: & bt.txt backtrace ^D $ ]]> Type the characters in the first line verbatim! Those are back-tics there! backtrace is a gdb command. You should enter it verbatim after the first line shown above, but it will not be echoed. The ^D (Control-D, that is, press the Control key and the D key together) will cause gdb to exit. This will leave you with a file called bt.txt in the current directory. Include the file with your bug report. If you do not have gdb available, you will have to check out your operating system's debugger. You should mail the traceback to the &WiresharkDevMailList; mailing list, or attach it to your bug report.

The Windows distributions don't contain the symbol files (.pdb), because they are very large. For this reason it's not possible to create a meaningful backtrace file from it. You should report your crash just like other problems, using the mechanism from .