Michal Čihař - Blog Archives for Gammu

Finding a GPL violation

As the communication in this case seems to be stuck and the issue is almost one year old, it's time to make bits of it public. The first post will just describe how I've discovered it, later will bring more details.

All started innocently with bug report on Gammu that it fails to work with some Sonim phones. We started to dig some information about what extensions does Sonim use and one of obvious ways was to try their software. I picked up software for Sonim XP3.20 Quest and started to look at it (if you are not going to install them, but want to look, you need unrar and unshield to unpack it). Actually all their software with exception of the one for XP2.10 Spirit is based on same code, so it does not matter that much which one you choose.

At first look the names of DLLs looked familiar to me and running strings on the DLLs just confirmed my suspicion - the phone which is not supported by Gammu bases it's official software on it. I was able to recognize at least seven DLLs derived from (GPL licensed) Gammu (they even use same names as Gammu modules had in that time):

  • At.dll
  • ATgen.dll
  • Common.dll
  • FBus.dll
  • IRDA.dll
  • ObexGen.dll
  • Serial.dll

To make the thing more interesting they use several other components released under free software licenses, where they also should provide sources for them:

  • ID3LIB.DLL - id3lib (LGPL)
  • WbXmlParser.dll- libwbxml (LGPL)
  • lame_enc.dll - lame (LGPL)

There might be more, but I did not want to spend more time on deep analysis, because I already had enough information.

Impressed by xz compression

I knew that xz (or lzma) provides better compression ratio than bz2 or others, but I never thought the difference might be so huge. Simply I was impressed after I've enabled xz compressed snapshots for Gammu - the bz2 compressed tarball has 5.4M while xz compressed on only 1.6M. Wow.

New year

It's new year (for almost 18 hours here) and it's time to balance a bit what has happened in year 2010.

I'm not going to expose details from my personal life and anything related to work, so all what remains are open source projects where I am active.

For phpMyAdmin it was year of quite big changes, most of them beeing agreed on Fosdem 2010. We have migrated to git from svn, what was great step forward and I really like the change. It was also decided to use gettext (or rather php-gettext) for translations in upcoming release. I can see this move (together with online translation service) has definitely attracted more contributors (hey, but there are still many languages not translated, you're welcome!). Also we've participated in Google Summer of Code 2010, what lead to several big projects being merged into our code base (see my summary for more details). All in all, we're heading to 3.4 release in first months of 2011, which will be quite major step and hopefully heading in right direction.

In Gammu and Wammu, there were lot of code improvements, most of them probably going into Gammu SMS Daemon (the latest one being unified SQL backend removing lot of code duplication). Another major improvement is The Gammu Manual covering everything from Gammu command line, through SMSD up to python and C API. On the other side I've bought me a Symbian based phone, which does not work with Gammu and I use Series60-Remote for that, so my interest in Gammu has declined a bit.

Even though I've started adopting some packages in Debian, so it looked like I will end up with much more than last year, but at the end I've decided I'm too overloaded with some of them (and don't use them anymore), so I've given some for adoption and got rid of nanoblogger (and nanoblogger-extra) and looking for somebody to pick up gpointing-device-settings. Maybe all mpd related packages will follow soon, because I currently do not use mpd, so it limits quite a bit my ability to test them.

And of course: Happy New Year 2011!

Automatic configuring of Gammu

I bear in my mind idea for automatically configuring Gammu for some time. It should not be that hard using udev, Bluez and other tools which we already have available on average Linux system.

Today afternoon I've finally found some time to play with that and it's almost done. Well it's not fully automatic right now, it will just generate configuration file with possible choices, but at least some help. For now only udev and Bluez is supported, but I will add support for libusb soon as well.

The new tool is called gammu-detect and looks at devices available in the system and outputs something, what can be used as configuration file (you can find example in the documentation).

Once it will make reasonable guesses what user actually wants, it might get integrated into libGammu so that other applications like Wammu can benefit from it as well.

CTest not submitting to IPv6 dashboard

For some time, I observed that Gammu test dashboard does not get updates from my Debian box. Looking the CTest logs, the problem was in using IPv6 even when the box does not have it enabled:

Failed to connect to 2001:1528:136:dead:beef::1003: Network is unreachable

Due to lack of time I ignored it, but it looks all what was needed is to update curl. The bug was caused by using c-ares resolver, which for some reason favors AAAA records even when the system has no IPv6.

New features in Gammu

I've just released new version of Gammu, which comes with some things, which are worth mentioning.

First thing is m-obex support (which I've already announced). Since last announcement, there were some improvements, but I'm affraid it still does not work, because it was not completely tested. So the very same request applies - testers welcome and we need feedback.

The second big change is universal SQL backend for Gammu SMSD, which consolidates code of former MySQL, PostgreSQL and DBI backends. It also adds option to configure SQL queries it will use. This was tested using usual testsuite, so it is working, but there still might be some glitches, which will need polishing before we can declare it stable.

Gammu documentation improvements

During the weekend, I've found some time to improve documentation for Gammu. One of user accessible things which did lack documentation are native file formats used by Gammu.

There is not that much of them as Gammu supports standard formats for most data (like vCard, vCalendar, iCalendar), but there are things where standard simply does not exists and we need to store that data as well. This is the case for backups (both data and SMS), where SMS backup format is used as well for files backend in Gammu SMSD.

So I went through the SMS backup internals and wrote the documentation. While reading the code I of course discovered quite obvious bug, which was for some reason undiscovered for very long time.

Gammu gets m-obex support

I've found some time to implement m-obex protocol based on documentation provided by samsyncro project. However I don't have any phone to test it, so any testers are welcome :-).

The testing should be quite easy - just get current Git version of Gammu (either using git or use snapshots) and try to use commands which manipulate with contacts and calendar:

gammu getallmemory ME
gammu getallcalendar
gammu getmemory ME 1
gammu getcalendar 1
gammu addnew test.vcf
gammu addnew test.vcs

In case you have not yet used Gammu with your phone, the configuration for USB cable should look like:

device = /dev/ttyACM0
connection = at

And for Bluetooth:

device = address of the phone
connection = blueobex
model = mobex

Of course there is no guarantee that any of the commands will work, because all I could verify is that code compiles and looks correct. It might as well do something bad to your phone, so backup is recommended.

Another step in Gammu documentation

I've just finished another step for new Gammu manual - it includes also documentation for gammu utility. It includes all content from the man page, reformatted and improved in some sections. So now the documentation does cover all important parts and can contain correct cross references.

The only problematic thing was to handle non dash starting commands in Sphinx. Unfortunately it does not seem to like this idea, so I had to invent some ugly hacks, which workaround that (just changing the regexps which sphinx.domains.std uses).

The man page will be from now on generated from this source as well.

Making Gammu use GLib

I had this topic in mind for quite a long time, but it got more recently more attention because of discussions on gammu-users mailing list. Gammu should use some library for do basic stuff like strings or date manipulations, logging and so on.

The reason is that having own implementation of all that is not really useful and just source of another amount of bugs. Currently mi intention is to use GLib, simply because I don't know any C alternative (though there are probably lot of C++ cross platform libraries).

Of course the biggest question is how to make the change, because it will be obviously intrusive and making such big changes will probably lead to several months of work without really making another release. Even if it will be done on separate branch (what would be most likely the case), developers will spend most of time on this issue and not much time will be spent on bug fixes (and backporting them).