Rob Gallagher
dwm and swarp
May 27th
One thing that I really like about dwm is that if you have multiple monitors it treats them somewhat like independent instances of the window manager. So you can keep your mail client open on one monitor and switch between your terminals and web browser on another, and vice-versa.
However this also applies to the mouse pointer, it does not move across when you switch monitors. Of course you may not always want this, but it’s sometimes handy to have the option. I believe that the gottox branch of dwm had this pointer-switching functionality, but dwm-gtx doesn’t seem to be actively maintained these days.
Enter swarp, another tool from the suckless bag of tricks. It’s a simple utility that “warps” the mouse pointer to a given coordinate on your screen.
To get it working with dwm, simply download the tarball, uncompress, compile and install. Like everything else from suckless the dependencies are tiny. Test it out from the command line by specifying different coordinates. Once your happy with the locations that the pointer jumps to, you can add these commands to your dwm config.h to switch from screen to screen:
static const char *warpleft[] = { "swarp", "100", "500" };
static const char *warpright[] = { "swarp", "1500", "500" };
Now you need to bind the commands to a key, I use the Windows key as a modifier for a lot of things since it is generally unused:
{ WINKEY, XK_w, spawn, {.v = warpleft } },
{ WINKEY, XK_e, spawn, {.v = warpright } },
Because my monitors vaguely face west and east, I chose w & e as the switching keys 
As usual, compiling, reinstalling and restarting dwm will apply the changes.
Setting up scponly
Mar 24th
In the past, if I wanted to create a restricted account for a user, to upload files via scp/sftp for example, I normally setup rbash with a defined set of commands. However, it’s possible to break out of an rbash environment quite easily.
Recently, whilst setting up an account for one of the Eirtakon guys to modify their drupal install, I decided to give scponly a whirl. This is a restricted shell that, as the name implies, only allows access to scp and sftp. It also provides a chroot mode (scponlyc) to lock users into a specified directory hierarchy, which I configured for this particular user.
Installation on Debian is simple:
aptitude install scponly
To enable the chrooted version of scponly, do:
dpkg-reconfigure -plow scponly
Unzip the chroot setup script and make it executable
cd /usr/share/doc/scponly/setup_chroot gunzip setup_chroot.sh.gz chmod 755 setup_chroot.sh
If you are on a 64 bit system, scponly is basically broken out of the box. You need to do a couple of things to make it work, the first is to apply this diff to setup_chroot.sh, it adds /lib/ld-2.7.so to the LDSO_LIST variable.
--- setup_chroot.sh 2010-03-24 18:53:15.000000000 +0000
+++ setup_chroot.sh.busted 2010-03-24 18:52:24.000000000 +0000
@@ -79,7 +79,7 @@
#
# we also need to add some form of ld.so, here are some good guesses.
#
-LDSO_LIST="/lib/ld-2.7.so /lib/ld.so /libexec/ld-elf.so /libexec/ld-elf.so.1 /usr/libexec/ld.so /lib/ld-linux.so.2 /usr/libexec/ld-elf.so.1"
+LDSO_LIST="/lib/ld.so /libexec/ld-elf.so /libexec/ld-elf.so.1 /usr/libexec/ld.so /lib/ld-linux.so.2 /usr/libexec/ld-elf.so.1"
for lib in $LDSO_LIST; do
if [ -f $lib ]; then
LDSOFOUND=1;
You can now run the setup script
./setup_chroot.sh
This creates a chrooted user and sets up the necessary environment.
Now set up /dev/null:
cd ~scponlyuser mkdir dev cp -a /dev/null dev/
For a 64 bit system, you need to copy across a few more supporting libraries into the chroot:
cd ~scponlyuser cp -p /lib/libncurses.so.5 lib/ cp -p /lib/libncurses.so.5 lib/ cp -p /lib/libdl.so.2 lib/ cp -p /lib/libc.so.6 lib/ mkdir lib64 cp -p /lib64/ld-linux-x86-64.so.2 lib64/
To restrict the user to only the path I want them to see, I set their home directory to /home/scponlyuser//drupal. The // has the effect of dropping them into that particular directory once they get chroot’ed, which is /drupal in the chroot environment.
I also wanted to let them have access to /var/www/eirtakon.com/drupal, but without symlinks or other nonsense. This can be done with the bind option in mount:
mount -o bind /var/www/eirtakon.com/drupal /home/scponlyuser/drupal
To test it out
sftp scponlyuser@longcat.spoofedpacket.net
Switching to NSD
Mar 7th
Whilst BIND is a nameserver I use nearly every day, it’s somewhat large and unwieldy being a reference implementation of the DNS spec.
Where possible, I always like to split out resolving and authoritative functionality into two seperate pieces of software. Unbound does a great job in the latter role – also from the authors of NSD, NLnetlabs – so I thought I’d give NSD a go on ns.spoofedpacket.net.
This machine serves only handful of zones, so it’s easy enough to migrate. The transition is made even simpler since NSD supports the old bind zonefile format out of the box. I decided to install NSD from source, following the tried and tested method:
cd /usr/local/src wget http://www.nlnetlabs.nl/downloads/nsd/nsd-3.2.4.tar.gz tar zxvf nsd-3.2.4.tar.gz cd nsd-3.2.4 ./configure make make install
The dependencies are very few, it should compile without much fuss on nearly any modern *nix system.
By default, all configuration files and zones go into /etc/nsd. There is also an nsd.conf.sample that you can use as a base config. The config file is extremely simple, for a basic setup you only need to look at the server: and the n-number of zone: sections. In the server: section, I only changed the location of the zone files:
zonesdir: "/etc/nsd/zones"
At this point, it’s always good practice to organise your zonefiles into directories according to their roles. Here is what I have:
/etc/nsd/zones/master /etc/nsd/zones/slave (nothing here yet) /etc/nsd/zones/master/forward /etc/nsd/zones/master/reverse /etc/nsd/zones/master/reverse/IPv4 /etc/nsd/zones/master/reverse/IPv6
If you have an old BIND install that you are replacing, it is just a simple matter of copying/moving the existing zonefiles to their new locations. The zones can then be configured in nsd.conf as follows:
# spoofedpacket.net
zone:
name: "spoofedpacket.net"
zonefile: "master/forward/spoofedpacket.net.zone"
notify: 193.1.193.194 NOKEY
provide-xfr: 193.1.193.194 NOKEY
name and zonefile are pretty self explanatory, just remember that the path to your zonefile is always prefixed with the zonesdir statement from earlier on. notify lists all the nameservers you wish to send DNS notifies to when a zone is updated. provide-xfr controls who can carry out zone transfers (AFXR) from your nameserver. The NOKEY statement tells NSD that no cryptographic keys are required to authenticate the notifies or zone transfers between your nameserver and the secondary nameservers.
Once you’ve finished editing nsd.conf, you must now compile your zonefiles into the binary format that NSD understands. This is one of the main reasons for NSDs speed and low footprint:
nsdc rebuild nsdc reload
Verify that nsd is running and serving zones:
pgrep -lf nsd dig @ns.spoofedpacket.net www.spoofedpacket.net
2009/2010 Winter and Spring Anime season
Jan 7th
So, whilst we’re all stuck indoors due to the snowpocalypse, it’s a good time to take a look at what’s been released and what’s going to be released in Japan over the coming few months. Things are somewhat thin on the ground, there’s a lot of the usual loli and h-game based stuff but a few things jump out as worth watching.
Durarara!:
From the makers of the excellent Baccano! (they must have a thing for !’s in the title). There’s a guy stamping on some ko-gal’s phone in the trailer, whilst laughing hysterically… I like this:
Dance in the Vampire Bund:
Oh, something about vampires. The premise looks interesting however, an extremely rich vampire from the Tepes family (as in, Vlad Tepes, Vlad the Impaler) pays off the national debt of Japan (!!) in order to get her own island which can be used as a safe haven for the blood drinkers of this world. She proceeds to make preparations for revealing the existence of vampires to the public at large, before some terrorists decide to attack and wreck their buzz:
Katanagatari:
A very nice period piece with some swordplay, interesting artwork and music. The director worked on Legend of the Galactic Heroes and Crest of the Stars, amongst other things:
Uchuu Senkan Yamato Fukkatsu-hen (Movie):
Power up the wave motion gun! After nearly 26 years of false starts there’s finally a new Yamato movie:
The Disappearance of Haruhi Suzumiya (Movie):
It goes without saying that this will be enormous.
Gundam Unicorn (OVA):
I’m saving the best till last. A new Yamato movie and now the first UC Gundam show since 1993. Mabye this season isn’t so bad after all. Neo Zeon are back and there is a Char-like character called …wait for it…Full Frontal. This is going to rock.
spoofedpacket.net signed
Dec 1st
I recently signed spoofedpacket.net, here’s the DS sets:
spoofedpacket.net. IN DS 15871 5 1 6D6B3C370091ECF38D81B2D91B54C7B2EB6D47E6 spoofedpacket.net. IN DS 15871 5 2 41D36F7DEC5827F650E772DE1DA33A219B3B994757DDF763830EBC12 E2DCEC80
And the keysets:
spoofedpacket.net 604800 IN DNSKEY 257 3 5 (
AwEAAa1qyDcvEEsXZYvzI5TwlJks8pK95OSE
RjMtg0aN/cBfpNeyyYwX1O5zQy1G13qklxYR
CbPHbbeZkxMxfVxc3pUSDOqYtu6IBhhPTv9Z
Gwnjn6CRBdKVrkdMI5ZPJ3uwvMj9yk6a9jjg
tUZZfIRkbURa/Q75AaqB8ihQN7pU5N9Tui0i
V3eoKZrVfc5mUDATnggSw/Pk7blHKn8OWwEJ
b7Q5Uulg4fmHYSxX2sTzt5kgZxWAVbaZ5IWn
XwMJkUN7kM9Lz04exn4JmpeMpfAo3+tyDC1F
LLJVPAk4KmhDKPhiY1y9yeZxLiloYh8KvG4b
W18D465/RQRkoLufF+/6htk=
) ; key id = 15871
