Harald Welte, has written on his blog about operating an Open Source GSM network at the recent HAR2009 conference. Photographs and a description and of the setup, run under license of the Dutch regulatory authority, are provided; essentially the setup consisted of a pair of BTS’ (Base Transceiver Stations) running at 100mW transmit power each and tied to a tree. In turn these provided access to the Base Station Controller (BSC), in this case a Linux server in a tent running OpenBSC. The system authenticated users with a token sent via SMS; in total 391 users subscribed to the service and were able to use their phones as if they were on any other network. Independent researchers are increasingly examining GSM networks and equipment, Welte’s work proves that GSM is in the realm of the hackers now and that this realm of mobile networking could be set for a few surprises in the future.

PostgreSQL 8.4 has been released with its usual collection of shiny new features including Window Function support which means that you can now do OLAP with an Open Source database (How nifty is that!) All the other bits and bobs are listed on PostgreSQL 8.4 Feature List

When doing embedded network development, its typical that you have the embedded device you work on connected to one network interface (eth1) while you are simultaneously connected to your corporate or home LAN and the internet via another interface (eth0 or wlan0).

The thing about embedded development is that you spend a lot of time rebooting the embedded device with new firmware which sends your PC’s network interface down and up which triggers a new DHCP request on that interface, which then proceeds to time out (often there is no DHCP server on the embedded device) before you have to manually assign the same static IP that you were using on the interface a few seconds before.

As it turns out there is a way to tell NetworkManager to keep its mitts off of a particular interface. Firstly, find the udi of the interface with the ‘lshal’ command. eg:

udi = ‘/org/freedesktop/Hal/devices/net_00_05_1b_ac_6c_03’
info.capabilities = {‘net’, ‘net.80203’, ‘wake_on_lan’} (string list)
info.category = ‘net.80203’ (string)
info.interfaces = {‘org.freedesktop.Hal.Device.WakeOnLan’} (string list)
info.parent = ‘/org/freedesktop/Hal/devices/usb_device_7a6_8515_0001_if0’ (string)
info.product = ‘Networking Interface’ (string)
info.subsystem = ‘net’ (string)
info.udi = ‘/org/freedesktop/Hal/devices/net_00_05_1b_ac_6c_03’ (string)
linux.hotplug_type = 2 (0x2) (int)
linux.subsystem = ‘net’ (string)
linux.sysfs_path = ‘/sys/devices/pci0000:00/0000:00:1d.7/usb7/7-1/7-1.6/7-1.6:1.0/net/eth1’ (string)
net.80203.mac_address = 21939121155 (0x51bac6c03) (uint64)
net.address = ‘00:05:1b:ac:6c:03’ (string)
net.arp_proto_hw_id = 1 (0x1) (int)
net.interface = ‘eth1’ (string)
net.linux.ifindex = 5 (0x5) (int)
net.originating_device = ‘/org/freedesktop/Hal/devices/usb_device_7a6_8515_0001_if0’ (string)
org.freedesktop.Hal.Device.WakeOnLan.method_argnames = {”, ”, ‘enable’} (string list)
org.freedesktop.Hal.Device.WakeOnLan.method_execpaths = {‘hal-system-wol-supported’, ‘hal-system-wol-enabled’, ‘hal-system-wol-enable’} (string list)
org.freedesktop.Hal.Device.WakeOnLan.method_names = {‘GetSupported’, ‘GetEnabled’, ‘SetEnabled’} (string list)
org.freedesktop.Hal.Device.WakeOnLan.method_signatures = {”, ”, ‘b’} (string list)

Then add this udi as an un-managed device to the [keyfile] section of ‘/etc/NetworkManager/nm-system-settings.conf’. eg:

[keyfile]
unmanaged-devices=/org/freedesktop/Hal/devices/net_00_05_1b_ac_6c_03

It should take effect immediately, and you shouldn’t even need to restart NetworkManager.

Note: Thanks to tambeti on #opensuse-gnome for the tip.