ctypes is a Python module to access foreign C types and functions, namely sysctlbyname(3). It’s easy to work with, here’s an example:

from ctypes import *

libc = CDLL("libc.so")

size = c_uint(0)

libc.sysctlbyname("kern.ostype", None, byref(size), None, 0);

buf = create_string_buffer(size.value)

libc.sysctlbyname("kern.ostype", buf, byref(size), None, 0);

>>> buf.value

'FreeBSD'

Python ctypes are available in Python 2.5 and up.

aimon is a system monitor much like MRTG, but specifically designed to monitor acpi_aiboost(4). acpi_aiboost(4) reports these values under FreeBSD and is present on several ASUS workstations and servers.

So, if you want nifty graphics about your server temperature, voltage and fan speed, this is for you. 

Here’s an example of how it looks like:

If you’re interested, the project home page is: http://fnop.net/~rpaulo/aimon/.

For those who don’t know, CalendarServer is a WebDAV server that implements the CalDAV extensions. This basically mens that you can register a bunch of users in your CalendarServer and using iCal or Chandler (to name a few) you can send invitations to meetings, share calendars and other nifty things that could help you organize better your company.

I assume familiarity with FreeBSD administration and some networking concepts.

What is Multicast DNS?
Multicast DNS is a recent protocol for doing DNS in a non centralized way, i.e., with multicast DNS, you can have a bunch of machines replying and querying hostnames ending in “.local”. Each machine is responsible for telling the others its hostname.
So, if machine A pings B.local, A will query B.local (via multicast) and B.local will reply to A. This should require no configuration from the user.

You can see that this model scales well and is convenient to have on a local network.

Service Discovery?
It would be cool if you could simply pick a computer from a list instead of memorizing its IP address, wouldn’t it? Several applications under Mac OS X allow this. If you use Mac OS X Leopard, you probably have already noticed that there are several network shares automatically added to the Finder list. This is Bonjour in action. Bonjour is what Apple calls Multicast DNS combined with Service discovery.

Multicast DNS implementations
Mac OS X comes with a multicast DNS implementation called mDNSresponder, but we won’t be using it with FreeBSD. Instead, we’ll use avahi, which I prefer.

First steps with Avahi
If you use FreeBSD as a workstation, you probably already have avahi installed. If not, simply do:

# portinstall avahi

After this, avahi is installed and ready to work. After enabling it in “/etc/rc.conf”, try giving it a try (yes, without configuring anything):

# /usr/local/etc/rc.d/dbus start
# /usr/local/etc/rc.d/avahi-daemon start

Right-click or Hold-click on the Mac OS X Terminal dock icon. You should see the menu entry “New Remote Connection…”. Click on it. You should see your FreeBSD server on the list:

Isn’t this cool? BTW, the key combination for this is Shift+Command+K.

So, how did this work? Check the directory “/usr/local/etc/avahi/services” on your FreeBSD system. It contains several XML files describing the service. The XML files themselves are very easy to write, just look at ssh.service.

Safari works with Bonjour too, so let’s try it. Go to Preferences and in “Bookmarks Bar” check “Include Bonjour”. You should now have a “Bonjour” folder like button on the Safari Bookmars Bar. 

You can configure a regular web server if you have one, but I don’t. What I have is mldonkey with a web interface. The following service description makes an mldonkey bookmark show up on the Bonjour list of my Safari and a Telnet entry show up on the Terminal:

<?xml version="1.0" standalone='no'?><!--*-nxml-*-->
<!DOCTYPE service-group SYSTEM "avahi-service.dtd">
<service-group>

  <name replace-wildcards="yes">%h mldonkey</name>

  <service>
    <type>_http._tcp</type>
    <port>4080</port>
  </service>

  <service>
    <type>_telnet._tcp</type>
    <port>4000</port>
  </service>

</service-group>

If you changed the port to 80, it would connect to a regular HTTP server on the FreeBSD system.

And this is what shows up on Safari:

BTW, Camino supports Bonjour too.

On to Bonjour file sharing

For the file sharing service, you need to install netatalk port which supports AFP (Apple File Sharing)

# portinstall netatalk

Then enable it in rc.conf (all you need is afpd running):

netatalk_enable="YES"
atalkd_enable="NO"
afpd_enable="YES"
papd_enable="NO"

And start it:

/usr/local/etc/rc.d/netatalk start

I use the following service description:

<?xml version="1.0" standalone='no'?><!--*-nxml-*-->
<!DOCTYPE service-group SYSTEM "avahi-service.dtd">


<service-group>
  <name replace-wildcards="yes">%h</name>

  <service>
    <type>_afpovertcp._tcp</type>
    <port>548</port>
  </service>

  <service>
    <type>_device-info._tcp</type>
    <port>0</port>
    <txt-record>model=PowerMac3,5</txt-record>
  </service>

</service-group>

Reload avahi:
# avahi-daemon -r

And now you should see something like this in the Finder:

Of course I promised it would look like an Xserve, so all you need to do is change “PowerMac3,5″ to “Xserve” and you’ll have your well earned $3000 Xserve

If you don’t really want an Xserve, pick one from the list:

• Xserve (or RackMac)
• PowerBook
• PowerMac
• PowerMac3,5
• Macmini
• iMac
• MacBook
• MacBookPro
• MacBookAir
• MacPro
• AppleTV1,1
• AirPort

Source: http://www.simonwheatley.co.uk/2008/04/06/avahi-finder-icons/

Finally, there are other services for which Apple uses Bonjour, namely, Screen Sharing (VNC) and Remote Speakers (AirPort Express), but I haven’t played with these.

I hope you enjoyed reading this, thanks.

On the FreeBSD machine:

1. Build & Install net/netatalk from ports.
2. Edit /usr/local/etc/AppleVolumes.default
3. Append: “/your_time_machine_path TimeMachine allow:your_user_name cnidscheme:cdb options:usedots” and replace your path and your username in the proper places.
4. Optionally, remove the “~” already present in that file if you don’t want to share users home directories.
5. Add “netatalk_enable=”YES”" and “afpd_enable=”YES”" to /etc/rc.conf.
6. /usr/local/etc/rc.d/netatalk start (nothing will be printed).

On the Mac OS X machine (running Leopard, of course):

1. Mount your remote volume. Command+K on the Finder and then type: “afp://<machine IP address or local hostname if you have a local DNS server>”. You can’t type the machine name because we’re not using multicast DNS.
2. Build a sparse bundle image using “Disk utility” (HFS+ case-sensitive formatted). Usually, the size should be something that gives you enough room for expansion. If you want to backup your whole MacBook/iMac/etc. disk, you can set the sparse bundle image size the same as the disk your are backing up.
3. The name of this image is important. It should be “Your_Computer_Name_MACAddress.sparsebundle”. Check your computer name from the “Sharing” section of “System Preferences” and the MAC address comes from the interface you’ll be using to do the backup. I really recommend using your Wired interface. Check the MAC address via ifconfig(1) or via the “Network”  section of “System Preferences”. E.g., if you’re John Doe, have a MacBook and your MAC address is 00:01:02:03:04:05, your file should be named “John Doe’s MacBook_000102030405.sparsebundle”.
4. On the Terminal, type “defaults write com.apple.systempreferences TMShowUnsupportedNetworkVolumes 1″. This is the crucial thing.
5. Go to “System Preferences”, “Time Machine” and enable it. The networked volume will now show up on the list.
6. Before selecting the volume on which you’ll dump the backup, copy the sparse bundle file you’ve created to your networked volume called “TimeMachine”.
7. Select the networked Volume from the Time Machine volumes list.
8. Initiate the backup!

Enjoy!

EDIT: As Remko points out in the comments, the MAC address is not restrictive. So, if you want to backup via wired interface and after that via wireless, Time Machine will work using both interfaces. I suppose that Time Machine inspects all MAC addresses in your machine and then searches a sparse bundle in the networked volume that matches.

I’ve been asked by several people to make available a patch for my recent take on the FreeBSD/i386 EFI boot loader. I’m also making available binaries for i386.

So, if you have a Core Duo/Solo MacBook (Core 2 won’t work yet, sorry) and want to try it out, do the following:

• Install rEFIt.
• Download http://people.freebsd.org/~rpaulo/boot.tgz.
• Extract boot.tgz to your / HFS+ partition (don’t worry, rEFIt will find it).
• Reboot.
• Select /boot/loader.efi from the rEFIt boot prompt.

One thing worth playing with is the ‘col’ command I just added. It basically changes the screen resolution. So here’s your chance to have something super leet: a FreeBSD boot loader at 1280×800 or more! Also, EFI will make your HFS+ partition avaiable to the boot loader, so doing an ‘ls’ will really show your files.

Oh, the source code? Here: http://people.freebsd.org/~rpaulo/efi.tgz.

One final thing: I’m still working on kernel booting, so don’t expect it to work.

Apparently, I couldn’t make it work for last years’s Summer of Code, but now something works. I was able to boot loader.efi on my MacBook and see a “FreeBSD/i386″ boot message. Yay! Unfortunately, there seems to be a bug in (probably) the FORTH library and it sometimes hangs or, if it doesn’t hang, it displays a lot of garbage.

So, you have a MacBook and want to try this out? Great! Here’s the procedure:

• Grab loader.efi from http://people.freebsd.org/~rpaulo/.
• Install rEFIt.
• Copy loader.efi to, for example, /efi/freebsd/loader.efi.
• Reboot and select loader.efi from the rEFIt boot menu.

Don’t expect nothing fancy though.

UPDATE: the bug is not in the FORTH library as I originally though.

If you have this hardware and would like to help with the effort, please email me.

The effort is being revision controlled at //depot/user/rpaulo/lii/.