For the last few days I've been learning more about UPnP and testing it with the few devices I have around the house. One of these is a cheap ADSL router, which apparently has the lamest UPnP stack on in existence. It does however support the WAN IP Connection interface, so you can use UPnP to get the external IP address and manipulate the port mapping. I'll skip over the horrific security violations this involves, because it's a useful demonstration that the majority of people will be able to test.

Today we'll start simple and get our external IP address using GUPnP. The first thing to be done is to create a Control Point, which in the UPnP model handles discovery of resources, be them devices or services (a device can have multiple services). When creating a control point you can specify the URN of the resource you want to target. In this case we want all services providing WANIPConnection so we'd use urn:schemas-upnp-org:service:WANIPConnection:1. If you want to browse for all services then use ssdp:all (SSDP being the Simple Service Discovery Protocol).

static GMainLoop *main_loop;

int
main (int argc, char **argv)
{
  GError *error = NULL;
  GUPnPContext *context;
  GUPnPControlPoint *cp;
  
  /* libsoup requires threading, so we have to initialise it */
  g_thread_init (NULL);
  g_type_init ();

  /* Default GLib context, default host IP, default port */
  context = gupnp_context_new (NULL, NULL, 0, &error);
  if (error) g_error (error->message);

  /* Create a control point targeting WAN IP Connection services */
  cp = gupnp_control_point_new
    (context, "urn:schemas-upnp-org:service:WANIPConnection:1");
  /* Tell the control point to start searching */
  gssdp_resource_browser_set_active (GSSDP_RESOURCE_BROWSER (cp), TRUE);

  /* The service-proxy-available signal is emitted when any services which match
     our target are found */
  g_signal_connect (cp,
		    "service-proxy-available",
		    G_CALLBACK (service_proxy_available_cb),
		    NULL);
  
  /* Enter the main loop */
  main_loop = g_main_loop_new (NULL, FALSE);
  g_main_loop_run (main_loop);

  /* Clean up */
  g_main_loop_unref (main_loop);
  g_object_unref (cp);
  g_object_unref (context);
  
  return 0;
}

static void
service_proxy_available_cb (GUPnPControlPoint *cp,
                            GUPnPServiceProxy *proxy)
{
  /* ... */
}

Now we have an application which searches for the service we specified and calls service_proxy_available_cb for each one it found. Now, to get the external IP address we need to invoke the GetExternalIPAddress action. This action takes no in arguments, and has a single out argument called "NewExternalIPAddress". Yes, the naming scheme is stupid. GUPnP has a set of methods to invoke actions -- which will be very familiar to anyone who has used dbus-glib -- where you pass a NULL-terminated varargs list of (name, type, value) tuples for the in arguments, then a NULL-terminated varargs list of (name, value, return location) tuples for the out arguments. A simple implementation would be as follows.

static void
service_proxy_available_cb (GUPnPControlPoint *cp,
                            GUPnPServiceProxy *proxy)
{
  GError *error = NULL;
  char *ip = NULL;
  
  gupnp_service_proxy_send_action (proxy,
				   /* Action name and error location */
				   "GetExternalIPAddress", &error,
				   /* IN args */
				   NULL,
				   /* OUT args */
				   "NewExternalIPAddress",
				   G_TYPE_STRING, &ip,
				   NULL);
  
  if (error == NULL) {
    g_print ("External IP address is %s\n", ip);
    g_free (ip);
  } else {
    g_printerr ("Error: %s\n", error->message);
    g_error_free (error);
  }
  g_main_loop_quit (main_loop);
}

Note that _send_action blocks until the service has replied. If you need to make non-blocking calls then use gupnp_service_proxy_begin_action which takes a callback.

So, that is searching for services and invoking actions in GUPnP. Next time I'll cover subscribing to state variables, and routers which can't count.

NP: Folk But Not Folk, Various

To download it you can either grab the tarball or fetch the bzr tree.

Maybe it's time to get a dedicated build machine, my poor laptop gets quite toasty when building Poky. Then again it seems happy enough, so maybe I should just use an external keyboard to avoid boiling my hands.

NP: Oneric, Boxcutter

• Update the status bar after uploading
• Add a Switch User menu item
• Add Add/Remove buttons to the image pane
• Install the Nautilus extension to the new extension path
• Don't select groups when the name is clicked
• Don't display errors when posting to moderated groups
• Show a warning on exit if there are images to upload (thanks Germán Póo-Caamaño)

The tarball is here, and packages for Debian have been uploaded.

• Add Send To Group options
• Add Privacy and Safety options
• Use a multi-line entry for the Description field
• Show the user's name in the status bar
• Fix the resizing of the preview

The tarball is here, and packages for Debian have been uploaded.

mobile-2.24

This changes GConf and EDS to use the DBus ports, and provides meta-mobile-platform which builds the complete platform.

pimlico

This builds Contacts, Dates and Tasks, providing meta-pimlico.

matchbox

This builds Matchbox Panel, Matchbox Desktop, Matchbox Keyboard and Matchbox Window Manager, providing meta-matchbox.

Also, Poky is building images nightly with the complete platform in, which will let you build and test software in a PDA-style environment with QEMU, running on x86 or a number of ARM-based devices (such as Nokia N800, Sharp Zaurus or OpenMoko).

Last week at the Collaboration Summit in Austin (which I couldn't attend for personal reasons) there was a day-long GNOME Mobile meeting, as a result of which there is now a long list of packages which need to be considered for addition to the Platform (such as HAL, Gypsy and Geoclue), and a few changes (such as replacing gnome-vfs with gvfs). I hope to review the proposals fairly shortly, so that we can hopefully make an initial GNOME Mobile 2.24 platform release alongside the Desktop release in September.

In other news, this is exactly what the Internet is for.

NP: Blue Moon Station, Solar Fields

Man the lifeboats. The idiots are winning. Last week I watched, open-mouthed, a Newsnight piece on the spread of "Brain Gym" in British schools. I'd read about Brain Gym before - a few years back, in Ben Goldacre's excellent Bad Science column for this newspaper - but seeing it in action really twisted my rage dial.

Charlie Brooker in The Guardian gets deservedly angry over Brain Gym, after seeing an article about it on Newsnight (1, 2 on YouTube). The creator of Brain Gym was destroyed by Paxman, rather too easily to be honest.

NP: Voices, Vangelis (via Last.fm)

12 weeks and one day, to be precise.

Vicky is pregnant!

In other news, the new Lightroom 2 beta is very nice.

I need SMTP AUTH and TLS, which means nbsmtp, masqmail, and nullmailer are out. I want a local queue for when I'm not online which means esmtp, ssmtp, msmtp, and nullmailer are out (I'm not convinced that msmtp's queue scripts are reliable enough). Surely there must be a simple SMTP relay which will reliably manage a queue if the mail cannot be sent! If not, does anyone know of a good guide to configuring Postfix or Exim to do this?

Because I'm fairly lame there are not matching Debian packages yet, but I'll get around to that tomorrow. In other news, a very nice man called Ian Lawrence wrote a buzzword-compliant tutorial where he uses Gypsy to talk to a Bluetooth GPS, tests it with my Gypsy Status 10-minute hack, and then uses Django to redirect the user to the relevant geohash.org page.

NP: Remembranza, Murcof

Original source, although the image was just pulled from the site.

That said, I still haven't forgiven you for some of the finer details of libecal Federico. :)

1. I'm using emacsclient, and when I close the last frame Emacs quits. With XEmacs when in server mode the process continues when the last frame is closed, anyone know how I can get Emacs to do this too?
2. Emacs appears to be moving the mouse pointer when I open a new frame. This is totally frustrating not only because I use sloppy focus, but also because its moving the point to the wrong frame. How can I turn this off?

Help greatly appreciated!

First, implementation details will be announced as a major, if not the main, feature. The shining example is "based on DBus". Yes, DBus is great. Yes, ORBit is a dying technology for something as simple as transfering a few strings between two processes. But this is an implementation detail. I'd prefer a project using DBus instead of another incredibly complicated IPC, but implementation details are typically not something to get excited about.

Often this first point gets out of control and suddenly the point of the project is to design a DBus interface, not to write real working code. Of course, an interface without any code behind it, without any reference implementation, without several applications and different users, is bound to be broken somewhere. But you'll never know until it is too late and you've labelled the interface as STABLE. Learn from DBus itself, anyone who followed the project before 1.0 knows that the core concepts were rewritten several times before it was finally marked as stable.

Spreading basic FUD is fairly common too. "EDS is not efficient concerning network bandwidth" doesn't make sense, because EDS is a local daemon. When it does talk over the network, it's fairly sensible. The LDAP (and Groupwise/Exchange I believe) backend maps EDS searches to native searches so that only the requested items are fetched. Backends such as WebCal have no option but to fetch the entire file, because that is how they work. "EDS is not efficient concerning memory usage" is rather vague, and if you interpret it as "private dirty memory usage is unreasonably high when in use" then in my opinion that is untrue and I have Massif logs to back me up.

If these points were true, they'll generally be fixable within EDS. The default local calendar backend is implemented as an iCalendar file on disk, which is parsed into memory in its entirety on startup. This certainly works well for a basic implementation but should be replaced with a database of some sort, a simple one which stores a hash of UID to event would reduce memory usage for large calendars. Add to that a cache of start and end times to optimise that common case and the end result is probably both faster and uses less memory, for a few days work.

Occasionally complaints are spot-on, but EDS isn't immutable and whilst starting a new project from scatch may be more fun, please think of everyone else. EVCard is over-complicated and yet tragically crippled, whilst EContact tries to be clever but generally gets in the way. Luckily we can write a new contact object which is easier to use. The query language is limited, but Milan Crha of Red Hat fame has been chipping away and now it's more flexible without breaking existing applications. Maybe someone can come up with a good replacement language, and the old language deprecated.

I'll summarise what I'm trying to say.

• EDS isn't perfect, we all know that.
• However, EDS also isn't immutable. It can be fixed.
• If you find bugs or bad design in EDS, please file a bug report.
• If you have spare time to start a replacement project, please briefly consider the possibility of working on EDS first. The code isn't that scary, honest (especially the DBus port when I get around to merging it).
• If you still want to start a replacement project, at least be polite and inform the evolution-hackers mailing list that you are starting a project to replace it. You never know, there might be common ground that we can both work on.

NP: Kharah System, Hereill

Now that the basics are in place, I'm looking for other alpha-testers. Experience with Python is a requirement at the moment as there is no UI or configuration file yet. That said, if this application sounds like it could be useful to you then please email me.

NP: !K7, Various

• Bathroom scales
• A safe
• An Orange Pay As You Go SIM
• A wooden chopping board
• A Bluetooth headset
• Six iPod cases
• A Bodum teapot
• A radio walkman
• A Sharp portable minidisc recorder
• A Nikon APS camera
• Five belts
• Two boxes of word fridge magnets
• A 802.11g CardBus card
• An external USB sound device

It sounds a little like the Generation Game, I know. Combined with a bin bag full of junk, I can actually see the bottom of my drawers now!

Feedback on what magic strings should be detected would be great too. Currently it detects "today", "tomorrow", "yesterday", "this [weekday]" and "next [weekday]". Next up is "by|due|on [local date representation]", but what else would be useful?

• Fix various crashes in the preferences dialogs (thanks Matthew Martin)
• Translate the genres (thanks Brian Geppert)
• Add a paused track state (thanks Brian Geppert)
• Use the system icons for play/record (thanks Micharl Monreal)
• Many many translations!

Thanks to everyone who helped with Sound Juicer 2.22, there has been a huge influx of new contributors thanks to the GHOP and gnome-love projects.

So, anyone want to make an offer? I'll put it on eBay if nobody wants it, but I thought I'd offer it out to the Planets first. If anyone is interested ping me and I'll go and turn it on to double-check the specifications.

NP: Sounds Like Murcof, Last.fm

Poky 3.1 is released! We've been hard at work for this one, mainly deep in the guts to make it more portable and powerful. Of interest to GNOME developers is that Pinky is shipping a complete GMAE 2.20 platform, and a plugin for Anjuta to make building and deploying software for your target device trivial.

We've also got a sweet new web site and possibly the cutest mascot ever. I, for one, can't wait to stroke a plush Beaver.

The readers are never wrong. Repulsive, maybe, but never wrong. - Piers Morgan, as editor of the Daily Mirror, referring to how he lost circulation due to the paper's stance against the Iraq invastion.

Flat Earth News is a great book, and I can recommend it to everyone who is disappointed with the state of global journalism, and even more to anyone who thinks journalism is in general doing a good job.

• Don't loop if the selected music directory doesn't exist (Matthew Martin)
• When editing the album artist, unset the sortable artist name
• Remove deprecated calls in BaconVolume (Michael Terry)

NP: Untrue, Burial

OFFERED: 7 Blank Dual Layer DVD+R

was using them for xbox 360 games however found they failed alot. ideal for home movies or backing up data.

NP: Workmen digging up my road the bastards, Thames Water (photo)

NP: Mishaps Happening, Quantic

Yes, libnotify, I'm looking at you.

NP: Out of Season, Beth Gibbons

• Write extracted audio to a temporary file and then rename (Matthew Martin)
• Disable the Eject button if the drive cannot eject (David Meikle)

The good news is that there are now Contacts, Dates and Tasks packages for Chinook, also known as ITOS 2008, also known as the software on the N800 and N810. Sorry it took so long!

But recently it's been becoming quite useful. For large companies it generally appears to be company policy that contact with open source projects is done via anonymous email domains, like GMail. This obviously makes it tricky to guess where someone is from when they appear on a mailing list... but LinkedIn to the rescue. Search for a name and hey presto, their CV!

NP: Artists Like: Amon Tobin, Last.fm

• Add a Disc Number field, and magically populate it (Matthew Martin)
• Add content/* media types for Nautilus (Matthias Clasen)
• Set a11y relationships on the cluebar (thanks Rich and Willie)
• Fix play/pause (Bill O'Shea)
• Handle the cdio element not being cdparanoia