Centroid.EU Blog

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SVPradio 100th show next Wednesday

February 28th, 2013

Be sure to check out SVP Radio on Wednesday March 6th, starting at 6PM Eastern North American time. We have made a few changes which allow listening through the browser, and it may even work on an iPhone.


My first video entry

February 28th, 2013

I have made a video entry introducing my blog. I recorded off the webcam and converted the .avi to theora with ffmpeg2theora. A Firefox browser should be able to run this. It works on my OpenBSD box.

So yeah bad hair day!

This is what I use to record this with:


ffmpeg  -f sndio -i rsnd/0 -s 320x240 -f video4linux2 -i /dev/video0  -r 30 $OUTFILE 
It's a 12 euro mic and a 30 euro webcam...that says it all.


Teleworking: Mrs. Mayer you're (still) wrong

February 28th, 2013

Recently the news of Marissa Mayer (CEO of Yahoo) pulling all teleworkers at their organization back to their own corporate headquarters, struck me. I found it as wrong but discussion with a few californians on IRC they were of the perception that workers at yahoo who teleworked from home got a free paid vacation. BBC made an article about it.

I work from home and work is 6 timezones away in another hemisphere. This comes to my benefit though because I'M able to do technical maintenance on the computers at 4AM when it's 10AM here. This allows me to upkeep a "day" lifestyle, none of that 12 hour-days insanity that I did in my 20's. In fact everything is a lot more relaxed in operations so that we can draw benefits from me working from 6 timezones away.

Sure there is days I wished I could have been a bit more productive or had a buddy help me with something, but I believe my time is very productive. Another add-on to that is that I only work 30 hours a week and cannot do more because of illness (my doctor recommends this much). However working from home requires discipline. That's why I have an "office", a dedicated room in the apartment where I do my daily/eveningly tasks. This apartment is relatively new and I did some work out of a 1-room apartment for a few months, I'm glad that is behind me.

So I would say to Mrs. Mayer "you're not being fair to teleworkers". As every situation is different, and teleworkers have a strange but effective benefit.

Related articles found with search on this blog:


Donation time again

February 24th, 2013

Roughly the same time as last year.

  • OpenBSD gets 50 euros, for OpenBSD 5.3
  • FreeBSD Foundation gets 250 dollars in memory of Dan Moschuk, who was a FreeBSD committer and a friend of mine.
  • And another friend of mine gets 50 dollars or so for hosting SVPradio.com online radio stream. It's our 100th show on March 6th, 2013, and I promised I'd get him a bit of money in appreciation.
  • .
So I'm really into this by now, when there is a project that I see sense in giving money I give them money :P. Also one has to understand that I use OpenBSD and FreeBSD at work, so these projects help me make my money so why shouldn't I share a little of that? I think it's right and justified.


Firefox does DNS prefetching in OpenBSD

February 19th, 2013

I did not know this. And I noticed it today with packet dumping on my firewall. In german I would say "Das ist eine Sauerei!". Anyhow I googled a little and found this helpful blog. Basically what DNS prefetching is, is that when you visit a website and that website happen to have the link http://www.centroid.eu on it the browser would conduct a lookup of this Internet name and caches it. It could speed up things but I think it's a privacy invasion on my part because I look at an offline wikipedia here and the citations show someone sniffing outside my link what page I'm looking up by correlating. Yes I'm paranoid and it's not their business.


Introducing Fire Curses client

February 17th, 2013

The fire curses client (firec) is what I did while I was at my parents after the apartment fire. It allows me to IRC in a semi-windowed environment. Browse and download the source here:


Wildcarddnsd BETA 7 released

February 17th, 2013

I got all the patches that I had and put them in tweaked it a little yesterday and tagged the source tree. I made a mistake with the branch tag but that was easy to fix here is how I did it:

cvs tag -b -r OLDTAG NEWTAG     # puts a new tag on the old position
cvs tag -d OLDTAG		# removes the old tag
So here are the new things from previous wildcarddnsd release:
Changes in BETA_7 from BETA_6
 	- remote (sys)-logging feature with HMAC message verification
 	- change to Berkeley DB 4.6+ on BSD hosts (Linux had it already)
 	- allow numerous copies of wildcardnsd to pre-fork (-n flag)
 	- AXFR master code (this allows a bind9 slave to work with wildcarddnsd)
	- fix an integer overrun in parse.c which prevented big endian hosts to
	 make use of ANY replies and AXFR
 	- SRV RR support
 	- left sourceforge.net around August 14, 2012
 	- Mac OS X compiles now, but has not been tested with queries
Yes I'm not hosting at sourceforge.net anymore. I managed to leave them just before my old apartment building's fire and just before SF was sold. I do my own hosting of the sources and cvsweb and so on. Because of that decision I follow EU export laws not US export laws.

The next BETA release will likely happen around Nov 29, 2013 right on W's birthday (BETA_8 and 8 years old). I'm aiming for yearly releases and at BETA_10 I hope to have enough stuff in there that I can call it RELEASE_1 but we'll see. Enjoy these changes you can download the new snapshot (called 0.7.0) from here.


Reinstated CVSWEB for my programs

February 15th, 2013

I have ported the viewvc to lighttpd configuration and now my programs code history is viewable again. I will be committing new stuff shortly, which hopefully will reflect in these.

Feel free to check these out. I'll be rolling a new BETA release for wildcarddnsd soon.


My new IPv6 setup

February 14th, 2013

Happy Valentines day. I'm spending it alone with IPv6 :-). But I want to show you what I did and perhaps you have a few hints for me on how to improve it.

I have a Fritz!Box router (a home consumer router) which costs around 100 euros. I got mine for free with the new plan with M-Net my provider. M-net provides IPv6 on a test basis and since I can't get a static IP anymore with them I'm using it insteads of the IPv6 tunnel I used to have. This is what my network looks like now:

                Simplified IPv6 Network at Centroid.EU

                      | Gaia      |
                      | Luna (vm) |
                      | Mac OS X  |
                      |           |
  +-----------+       +-----+-----+                             +----------+
  |           |       |           |                             | Fritz.box|
  | Jupiter   |_______|  Uranus   |____________| 3270     |
  | OpenBSD   |       |  OpenBSD  |         Fritz.repeater      |          |
  |           |       |           |                             |          |
  +-----------+       +-----+-----+                             +-----+----+
                            |                                         |
                      +-----+-----+                                   |
                      |           |                                Internet
                      |  Mars     |
                      |  OpenBSD  |
                      |           |
The fritzbox announces IPv6 through route advertisements and delegates a /62 from the /56 prefix that M-Net provides me with. This /62 is given through DHCPv6 so I had to install isc-dhcpd from the ports on openbsd to make it work. However I faced a dillemma how does Uranus on the fritzbox facing interface know it's IPv6? I wrote a small script to enable it with rtsol and also the script adds rtadvd for automatic discovery on Jupiter, Mars, Gaia and Luna. I'm going to show one of these as an example. First to Uranus though, it's /etc/hostname.em5 interface looks like this:
# more /etc/hostname.em5
And I've written the /root/update-rtadv.sh script quickly so it may be buggy, but it works across reboots:

export PATH

/usr/local/sbin/dhclient -6 -P -D LLT  em5

PREFIX=`grep iaprefix /var/db/dhclient6.leases  | tail -1 | awk '{print $2}' | awk -F/ '{print $1}'`

EM0=`echo $PREFIX `
EM1=`echo $PREFIX | sed -e 's/:8fc:/:8fd:/g'`
EM2=`echo $PREFIX | sed -e 's/:8fc:/:8fe:/g'`
EM3=`echo $PREFIX | sed -e 's/:8fc:/:8ff:/g'`

(cat < /etc/rtadvd.conf

/etc/rc.d/rtadvd restart

route delete -inet6 default

while :: ; do
        ifconfig em5 | grep "inet6 2001:" 
        if [ $? -eq 1 ]; then

        sleep 10

backprefix=`rtsol -d em5 2>&1 |\
grep "received RA from" |\
awk '{print $4}' |\
awk -F:: '{print $2}'`

frontprefix=`ifconfig em5 | grep "inet6 2001:" | awk '{print $2}' | \
awk -F: '{print $1 ":" $2 ":" $3 ":" $4 ":" ; }'`

/sbin/route add -inet6 default $frontprefix$backprefix

exit 0
So when I'm on jupiter and I run a continuous ping6 on io.solarscale.de, it looks like this:
16 bytes from 2a01:4f8:d13:1980::22, icmp_seq=11 hlim=56 time=14.069 ms
16 bytes from 2a01:4f8:d13:1980::22, icmp_seq=12 hlim=56 time=17.013 ms
16 bytes from 2a01:4f8:d13:1980::22, icmp_seq=13 hlim=56 time=15.712 ms
16 bytes from 2a01:4f8:d13:1980::22, icmp_seq=14 hlim=56 time=14.167 ms

16 bytes from 2a01:4f8:d13:1980::22, icmp_seq=95 hlim=56 time=35.225 ms
16 bytes from 2a01:4f8:d13:1980::22, icmp_seq=96 hlim=56 time=14.689 ms
16 bytes from 2a01:4f8:d13:1980::22, icmp_seq=97 hlim=56 time=15.765 ms
16 bytes from 2a01:4f8:d13:1980::22, icmp_seq=98 hlim=56 time=14.213 ms
--- io.solarscale.de ping6 statistics ---
99 packets transmitted, 19 packets received, 80.8% packet loss
round-trip min/avg/max/std-dev = 13.973/16.219/35.225/4.611 ms
As you can see it ping'ed across a reboot and that means that all IP's and routes were configured correctly. On Mars I have an rtsol setup to get its IPv6 and it's /etc/hostname.gem0 looks like this:
mars$ more /etc/hostname.gem0
I had to also enable rtsold in /etc/rc.conf.local and enable route advertisements per sysctl.conf. The configured interface gem0 on mars looks like this then:
mars$ ifconfig gem0
gem0: flags=8863 mtu 1500
        lladdr 00:30:65:a1:ec:a6
        priority: 0
        groups: egress
        media: Ethernet autoselect (100baseTX full-duplex)
        status: active
        inet6 fe80::230:65ff:fea1:eca6%gem0 prefixlen 64 scopeid 0x1
        inet6 2001:a60:18e5:8fd:230:65ff:fea1:eca6 prefixlen 64 autoconf pltime 604697 vltime 2591897
        inet netmask 0xffffff00 broadcast
I still have to set up some sort of dynamic DNS for the IPv6 so that I can easily reach these hosts from each other since I can't remember their IPv6 address and on Gaia (the mac os x) the IPv6 keeps changing due to privacy extensions. However for outgoing IPv6 this setup works. Incoming is blocked at the fritzbox router anyhow and I haven't figured out how to set the IPv6 firewall rules right yet. I've sent AVM the maker a support email after consulting with M-Net.

I hope this helps the next person and if you have improvements let me know in the comments or mail me directly. Thanks.


I've moved

February 13th, 2013

Last night was the first night in my new apartment. Everything went well during the move and I got Internet yesterday at around noon. Here is a picture of my workbench and new stand-up table. I alternate between the two due to my lower back problems.

It looks a bit messy because I just dumped all my stuff on the table but I hope to rearrange things so that I can see the wood on the table.


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