Monthly Archives: June 2007

It hasn’t been long since the last gnome-vfs-obexftp release, but I thought it’d be good to get these fixes out before undertaking more invasive development. The new version is available from:

http://download.gnome.org/sources/gnome-vfs-obexftp/0.4/

The highlights of this release are:

• If the phone does not provide free space values in the OBEX capability object, do not report this as zero free space. This fixes Nautilus file copy behaviour on a number of Sony Ericsson phones.
• Fix date parsing when the phone returns UTC timestamps in the folder listings.
• Add some tests for the capability object and folder listing XML parsers. Currently has sample data for Nokia 6230, Motorola KRZR K1, and Sony K800i, Z530i and Z710i phones.

These fixes should improve the user experience for owners of some Sony Ericsson phones by letting them copy files to the phone, rather than Nautilus just telling them that there is no free space. Unfortunately, if there isn’t enough free space you’ll get an error part way through the copy. This is the best that can be done with the information provided by the phone.

Test Suite

As noted in the third point, I’ve started to build up a collection of capability and folder listing XML documents produced by various phone models. This serves a dual purpose:

1. Ensure that the capability object and folder listing XML parsers don’t regress between releases. It is impractical for me to test gnome-vfs-obexftp against all these phone models since I don’t have the hardware or time.
2. Give an idea of what information the different phone models provide, which should be useful when planning new features.

If you have an OBEX FTP capable phone that is not already in the test suite, it’d be useful if you could collect the data and file a bug. The information can be collected using the command line “obexftp” program (part of the “obexftp” package on Ubuntu). The following commands will give the capability object and root folder listing:

obexftp --bluetooth $BDADDR --capability
obexftp --bluetooth $BDADDR --list

It’d also be useful to get a listing for one or two other directories. If there is a memory card, it’d be useful to get that folder. For example:

obexftp --bluetooth $BDADDR --list "Memory card/"

It’d be most useful if the transcript of the various commands were included as an attachment. Feel free to censor personal information if you want (e.g. the phone serial number in the capability object, some non-default file names).

In particular, I wouldn’t mind getting information on phones with brands other than than Nokia or Sony to see what info they provide.

I’ve had a number of requests for USB support in gnome-vfs-obexftp. At first I didn’t have much luck talking to my phone via USB. Running the obex_test utility from OpenOBEX gave the following results:

$ obex_test -u
Using USB transport, querying available interfaces
Interface 0:   (null)
Interface 1:   (null)
Interface 2:   (null)
Use 'obex_test -u interface_number' to run interactive OBEX test client

Trying to talk via any of these interface numbers failed. After reading up a bit, it turned out that I needed to add a udev rule to give permissions on my phone. After doing so, I got a better result:

$ obex_test -u
Using USB transport, querying available interfaces
Interface 0: Nokia Nokia 6230 (null)
Interface 1: Nokia Nokia 6230 (null)
Interface 2: Nokia Nokia 6230 (null)
Use 'obex_test -u interface_number' to run interactive OBEX test client

With the change, I was also able to access the phone using the obexftp command line client. This seemed enough to start investigating a bit further. The OpenOBEX API for setting up USB connections goes something like this:

1. The app calls OBEX_FindInterfaces(), which returns a list of obex_interface_t structures that represent the different discovered interfaces.
2. The app picks one of the discovered interfaces (based on the manufacturer, product and serial number strings), then connects to it using OBEX_InterfaceConnect().

There are a number of issues with this interface though.

• If the phone doesn’t provide a serial number via its USB interface (like my 6230 doesn’t), the obex_interface_t structure is not enough to identify a particular phone.
• If the phone exposes multiple OBEX USB interfaces for some reason, OpenOBEX lists it multiple times. In the obex_test output shown above, there was a single phone attached – not three.
• There is no way to tell when phones are connected or disconnected. While HAL can do that job for us, there is no way to map from the device information provided by HAL to one of the discovered interfaces provided by OpenOBEX.

To sum up, it shouldn’t be difficult to hack support for USB connections into gnome-vfs-obexftp with URLs like obex://usb-N/ (where N is the number of the discovered interface), but there are a number of features I’d need to provide a good user experience:

1. The ability to ask OpenOBEX to connect to a particular USB device, rather than having to deal with its discovery interface.
2. A good set of udev rules to grant the needed permissions on common phones so they don’t need to find out why things only work as root.