OS X Patch for LANL AirPort Rules

LANL has had a policy of disallowing wireless networking. This is fine, I just had my LANL network location set to disable my built-in AirPort card. But, as a consequence of typical LANL overreaction, LANL has installed wireless monitoring equipment, so that even the few seconds between waking my laptop and switching to the LANL location may produce an alarm. Security may be an important thing to other people at LANL, but to me this is a stupid annoyance.

Since I am incapable of remembering to switch the location before I actually come to LANL, I have set up a kludgey system to set the LANL location automatically when I put my laptop to sleep at home. This is not extensively testing, and since these instructions involve commands as root, you should back up your data before you hose your data.

This is what to do:

• Set up appropriate locations under “Network” in Network preferences. The locations can be anything but one called “LANL” is required, which contains your LANL configuration and has AirPort powered down.

• Activate UI scripting. This is included in 10.3, and is available as a beta addition in 10.2. In 10.3, in System Preferences, select “Universal Access” and then check the box that says “Enable access for assistive devices.”

• Download this AppleScript (switchtolanl, plain Unix text) and put it in /usr/local/bin (you need to do this as root). Running this script (“osascript /usr/local/bin/switchtolanl”) will switch the network location setting to “LANL”.

• Download this executable (lanlonsleep, or get source) and put it in /usr/local/bin (again as root). This code is a modification of Apple's pm_callback demo code that will receive a message before the computer goes to sleep and calls the above script.

• Now make the executable start up automatically. Download this tgz archive (LANLonSleep.startup.tgz), unpack and put the contents in /System/Library/StartupItems. (From the command line, again as root, do “curl -O http://george.ph.utexas.edu/~dsteck/code/LANLonSleep.startup.tgz && tar xvzf LANLonSleep.startup.tgz -C /System/Library/StartupItems”.) Then start by saying “/System/Library/StartupItems/LANLonSleep/LANLonSleep start” or by rebooting.

• Finally, make the switch also when you shut down (actually, log back in after shutting down). Download this application (switchtolanl.app, the same AppleScript but saved as an application) and put it somewhere like /usr/local/bin. Then add this to your Startup Items under Accounts in System Preferences. This is not exactly the desired behavior, since the AirPort card may be powered on for a short time until this point in login. It is better to only put your computer to sleep and reboot when necessary.

• Test, test, and retest.